Spotting Errors: Grammar Rules, Examples and Practice
Spotting errors means identifying a grammatical mistake in a sentence. Grammar is the set of patterns that tells us how words fit together to express meaning. The task is to decide whether those patterns are used correctly and, if they are not, identify the part that needs correction.
Consider “The boy go to school every day.” The sentence describes one boy's regular activity. In this pattern, we say “he goes,” so the correct sentence is “The boy goes to school every day.” The error is in go, but the clue is in another part of the sentence: the boy.
This article builds that kind of reasoning from the beginning. You will first learn how a sentence works, then study the grammar behind common errors, and finally apply the rules to mixed questions. Each lesson includes the explanation needed to use it, so you can study the topic without opening a separate grammar article.
1. Understand the question format
An error-spotting question often divides a sentence into labelled segments. A segment may contain one word or several words. You select the segment containing the error, rather than the segment containing the clue that helped you find it.
Example: Identify the incorrect segment.
(A) The boy / (B) go / (C) to school / (D) every day.
Read the segments together before judging them. The boy is the subject, and go is the verb describing his habit. The required verb is goes, so the answer is B. Segment A supplies the clue, but it is already correct.
Some formats include a separate No error option. Select it when the complete sentence is grammatical; do not change a word merely because another word would sound more polished. Follow the stated instructions about whether there is one error, more than one error, or a replacement to choose.
The examples here use standard written English. Where a form depends on meaning, formality or British/American usage, the explanation says so. A preferred formal construction is not automatically the only grammatical construction.
2. Build the sentence from its smallest parts
Subject, verb and object
A subject is the person or thing the clause says something about. A verb expresses an action, event or state. An object is a person or thing affected by, or connected to, the action of a verb.
In “Riya reads a book,” Riya is the subject, reads is the verb, and a book is the object. To locate them, first find the action, reads. Then ask who reads and what she reads.
Not every sentence has an object. “The baby sleeps” is complete with a subject and verb. In “Riya is happy,” is links Riya to a description; happy is a complement, a word or group of words that completes the meaning here. It is not an object receiving an action.
Also, the subject is not always the doer. In “The book was borrowed by Riya,” the book is the subject, although Riya did the borrowing. This distinction matters when we later study passive voice.
Example: Find the main subject in “The box of old photographs is on the shelf.”
The sentence says something about the box. The words of old photographs describe its contents. Removing that description for a moment gives “The box is on the shelf,” which makes the subject and verb easier to see.
Singular, plural and grammatical person
Singular means one; plural means more than one. A student is singular, while students is plural. This difference affects nouns, some pronouns and some verb forms.
English also distinguishes first person (I, we), second person (you) and third person (he, she, it, they, or a named person or thing). Third-person singular includes he, she, it, Riya, and the box. This is the group that usually takes an -s verb in the simple present: “Riya reads.”
Do not shorten this to “every singular subject takes an -s verb.” I is singular, but we say “I read.” You can refer to one person, but we still say “You read.”
Phrases and clauses
A phrase is a group of words working together, such as in the classroom or the tall student. A clause is a grammatical unit built around a verb; the clauses we begin with have a subject and a verb. In “Riya reads because she enjoys stories,” there are two clauses: Riya reads and because she enjoys stories.
An independent clause, also called a main clause, can stand as a complete sentence. A dependent clause, also called a subordinate clause, depends on another clause. “Because she enjoys stories” leaves the reader waiting for the main statement.
This helps explain why each clause may need a different verb form. “Riya knows that her friends are waiting” correctly uses knows with Riya and are with her friends. Do not try to make every verb in a sentence agree with the first noun.
A word's job determines its part of speech
A part of speech is a category based on how a word functions. The same word can perform different jobs, so look at the sentence rather than memorising one label for every word.
| Part of speech | Its job | Example in a sentence |
|---|---|---|
| Noun | Names a person, place, thing or idea | The student needs help. |
| Pronoun | Refers to a person or thing without repeating its name | Riya arrived. She sat down. |
| Verb | Expresses an action, event or state | Birds fly. He is tired. |
| Adjective | Describes a noun or pronoun | This is a useful book. |
| Adverb | Adds information about a verb, adjective, another adverb or a clause | She spoke clearly. |
| Preposition | Expresses a relationship such as place, time or connection | The bag is under the desk. |
| Conjunction | Joins words, phrases or clauses | Riya and Aman stayed because it rained. |
| Determiner | Identifies a noun or indicates quantity or possession | The, my and three can introduce nouns. |
| Interjection | Expresses a reaction | Oh, I forgot my notebook. |
Articles (a, an, the) are determiners. Some school books group determiners under adjectives; the useful distinction here is their job before a noun.
Example: Compare “This is a fast train” and “The train moves fast.”
In the first sentence, fast describes the noun train, so it is an adjective. In the second, it describes the action moves, so it is an adverb. We do not add -ly simply because a word is doing an adverb's job.
3. Nouns: number, countability and possession
Forming singular and plural nouns
Many nouns form the plural by adding -s: book/books and chair/chairs. Nouns such as box and bus take -es: boxes and buses. With a consonant followed by y, change y to ies, as in city/cities; with a vowel before y, add s, as in boy/boys.
Some plurals must be learnt separately. We say child/children, person/people, man/men and woman/women. Some nouns keep the same form, such as one sheep/two sheep. Because patterns have exceptions, do not create an unfamiliar plural by guessing.
Example: Correct “Several childs were playing outside.”
Several tells us that there is more than one child, so we need the plural noun. The plural of child is children, not childs. The corrected sentence is “Several children were playing outside.” The plural verb were already matches children.
Countable and uncountable meanings
A countable noun names something we can treat as separate units: one pen, two pens, three pens. An uncountable noun names a substance, quality or general amount that is not normally counted directly in that meaning, such as water, advice, information or furniture.
We can count units of an uncountable thing: two glasses of water, three pieces of advice, or four items of furniture. The unit word becomes plural; the uncountable noun stays unchanged.
Example: Correct “She gave me two useful advices.”
Here advice means guidance, which is uncountable. We cannot attach two directly to advices. Introduce a unit: “She gave me two useful pieces of advice.” If the exact number does not matter, “She gave me some useful advice” also works.
Countability can change with meaning. Paper is uncountable when it means the material, but a paper can mean a newspaper or an academic article. Two coffees can mean two servings of coffee. Judge the meaning being used rather than declaring that a word can never be plural.
Nouns that look plural or behave unexpectedly
An -s ending does not guarantee a plural subject. “The news is encouraging” and “Mathematics is my favourite subject” use singular verbs. News is uncountable, while mathematics names a field of study.
Some items normally have plural forms, such as scissors and trousers. We say “These scissors are sharp,” but “This pair of scissors is sharp.” In the second sentence, the head of the subject, meaning its central word, is the singular noun pair.
Example: Correct “The furnitures in this room are new.”
In this meaning, furniture is uncountable. Write “The furniture in this room is new.” Both furnitures and are need correction, so this is a teaching example with two related changes, not a single-segment test item.
Possession and apostrophes
A possessive form shows ownership or a close connection. For a singular noun, usually add 's: “the student's bag.” For a regular plural ending in s, add only an apostrophe: “the students' bags.” An irregular plural without a final s takes 's: “the children's books.”
First decide how many owners there are. “The girl's bicycles” can mean several bicycles belonging to one girl; the plural bicycles does not tell us how many girls own them.
Example: Three students share a room. Correct “The student's room is upstairs” to reflect that meaning.
The owners are the three students. Make the noun plural first, then add the apostrophe: “The students' room is upstairs.” An apostrophe is not used merely to make a noun plural: three students, not three student's.
4. Articles and other determiners
A and an depend on sound
Use a or an with a singular countable noun when introducing one non-specific member of a group: “I need a pen.” Choose a before a consonant sound and an before a vowel sound. Listen to the next spoken word, which may be an adjective rather than the noun itself.
We say an umbrella and an honest person, because the next sound is a vowel sound. We say a university and a useful tool, because these begin with a consonant-like “y” sound. The spelling of the first letter alone cannot decide the article.
Example: Correct “She is a honest employee.”
The next word is honest, whose h is silent. Its first spoken sound calls for an. The corrected sentence is “She is an honest employee.”
Do not use a/an directly with a plural noun or an uncountable noun in its uncountable meaning. Write “some books” and “some information,” or introduce a countable unit: “a piece of information.”
The identifies something specific
Use the when the listener or reader can identify what you mean. “I bought a book. The book explains grammar” introduces an unspecified book and then refers back to that same book. Specificity can also come from description: “Please close the door beside you.”
The can introduce singular, plural and uncountable nouns: the chair, the chairs and the water in this bottle. Therefore, the decision is not simply “one thing versus many things.” It is also whether the thing or group is identifiable.
Example: Complete “I saw a dog near the gate. ___ dog was carrying a ball.”
The second sentence refers to the dog already introduced. Use “The dog was carrying a ball.” Using a dog again could suggest another dog.
When no article is needed
Plural countable nouns and uncountable nouns often take no article when used generally: “Books are useful” and “Water is essential.” Add the when referring to a particular group or amount: “The books on this shelf are useful” and “The water in this glass is cold.”
Most personal names, city names and language names normally have no article: Riya, Chennai, English. Names with established articles must be learnt as names, such as the United Kingdom. Avoid deciding every proper-name case from one general rule.
A singular countable common noun usually needs a determiner in an ordinary sentence. We say “She is a teacher,” not “She is teacher.” Established expressions such as go to school and be at home have their own patterns; “go to the school” can refer to a particular school building.
Quantity words: much, many, few and little
Use many and few with plural countable nouns: many questions, few mistakes. Use much and little with uncountable amounts: much time, little water. A lot of works with both: a lot of questions and a lot of time.
Few suggests not many, often fewer than wanted; a few means some. Similarly, little time suggests almost no time, while a little time means some time. The article changes the emphasis, so neither form is automatically an error.
Example: Correct “There are much books on the desk.”
Books names separate countable items and is plural. Change much to many: “There are many books on the desk.” The verb are already agrees with the plural noun.
Use fewer for a smaller number of separate countable items and less for a smaller amount: fewer errors, less noise. Measurements treated as amounts commonly use less, as in less than ten minutes. Do not apply the countable-noun test without checking whether the expression represents a total amount.
Each, every, either and neither
Each considers members individually; every includes all members of a group while still using a singular noun: each student, every student. Say “Every student has a notebook,” not “Every students have a notebook.”
Either can mean one or the other of two, while neither means not one and not the other. Before a singular noun, use either answer and neither answer. With of, the group is plural: “Either of the answers is acceptable.” Formal agreement is explained further below.
Quick check: Choose the correct words: “She gave me (a/an) useful suggestion and (a little/a few) information.”
Use a useful suggestion, because useful begins with a “y” sound, and a little information, because information is uncountable.
5. Pronouns: choose the right form and reference
Subject and object forms
Use I, he, she, we and they as subject forms. Their corresponding object forms are me, him, her, us and them. You and it do not change between these roles.
In “She helped him,” she performs the action and him is its object. After a preposition, use an object form: with her, for them, between you and me.
Example: Correct “The teacher praised Riya and I.”
The teacher is the subject, and the people praised form the object. Temporarily remove Riya and: “The teacher praised I” reveals the problem. Write “The teacher praised Riya and me.” The temporary removal is a checking method; keep both names in the final sentence.
The opposite applies to a subject: “Riya and I completed the task” is correct, because “I completed the task” is correct.
Possessive and reflexive forms
Use my, your, his, her, its, our and their before a noun: “This is her notebook.” Use mine, yours, his, hers, ours and theirs when the noun is not repeated: “This notebook is hers.” Possessive pronouns do not need apostrophes.
Its shows possession, while it's means it is or it has. “The company changed its name” needs the possessive form. Expanding it's to it is is a useful check when the meaning is uncertain.
A reflexive pronoun refers back to the subject: myself, yourself, himself, herself, itself, ourselves, yourselves, themselves. “Riya taught herself” means that Riya was both the teacher and the learner. Reflexives can also add emphasis: “Riya herself checked the answer.”
Example: Correct “Myself completed the report.”
There is no earlier subject for myself to refer back to. Use “I completed the report.” If emphasis is needed, “I myself completed the report” is grammatical, but the extra word is optional.
Make the reference clear
The word or idea a pronoun refers to is its antecedent. In “The students brought their notebooks,” their refers to the students. A pronoun should fit the intended person or thing and make the reference understandable.
“Riya told Meera that she had won” is grammatically possible, but she could refer to either person. If the context does not resolve this, repeat the relevant name: “Riya told Meera that Meera had won.” This repairs unclear meaning; it does not prove that every sentence with two possible antecedents contains a grammatical error.
Singular they is accepted when referring to a person, including someone whose gender is unknown: “Someone left their notebook.” The verb with someone is singular, but they retains its usual verb form: “Someone is waiting. They are outside.” Do not automatically mark their wrong after someone or everyone. Cambridge explains this use of they and them.
Who, whom, whose, which and that
A relative clause adds information about a noun. In “The student who called is outside,” who called tells us which student. Use who for people and which for things; that can introduce many defining relative clauses about either people or things.
In formal usage, who serves as a subject and whom as an object. “The candidate who answered impressed us” uses who because the candidate answered. “The candidate whom we selected accepted” uses whom because we selected the candidate.
Example: Choose who or whom: “The student ___ solved the puzzle received a prize.”
Inside the relative clause, the student performs solved. A subject form is needed, so write “The student who solved the puzzle received a prize.” Do not choose whom just because the word occurs in the middle of the sentence.
Object who is common and accepted in less formal usage: “The person who I met.” Whom is particularly associated with formal writing and placement immediately after a preposition: “the person to whom I wrote.” Cambridge distinguishes these formal and less formal uses.
Whose shows possession: “the student whose bag was missing.” A relative pronoun already fills a role, so do not duplicate it: “The book that I bought is useful,” not “The book that I bought it is useful.”
6. Subject–verb agreement
Agreement means choosing the verb form that fits its subject. The clearest differences occur with present-tense verbs and with forms of be and have. Before applying a rule, find the subject of that particular clause.
Ordinary present-tense statements
With third-person singular subjects, most main verbs take -s or -es: “She reads,” “He watches,” “The bus goes.” With I, you, we and they, use the base form: “They read.” A consonant plus y changes to ies: “She studies.”
Be has special forms: I am, he/she/it is, you/we/they are. In ordinary past statements, use I/he/she/it was and you/we/they were. Have becomes has with third-person singular subjects in the present.
Example: Correct “The children plays outside.”
Children is plural, although it does not end in s. Replace plays with play: “The children play outside.” The noun's number controls the verb; its final letter does not.
Extra words between subject and verb
A phrase such as along with, together with, as well as or of the students may separate the subject's head from its verb. Such a phrase does not automatically create a plural subject.
Example: Correct “The manager, along with the assistants, are attending the seminar.”
The main statement is about the manager. The assistants accompany the manager, but the phrase does not join two equal subjects with and. Read the shorter skeleton, “The manager are attending,” then repair it: “The manager, along with the assistants, is attending the seminar.”
The same reasoning gives “The principal, as well as the teachers, was present.” Do not extend the nearest-noun rule from either...or to these constructions.
One of, each of and every
In “One of my friends has arrived,” one is the head of the subject. The noun after of is plural because we choose one member from a group, but the main verb is singular because we refer to that one member.
Likewise, formal standard patterns include “Each of the students has a notebook” and “Every student is ready.” When each follows an already plural subject, that subject remains plural: “The students each have a notebook.”
Example: Correct “One of the players have forgotten the kit.”
The sentence refers to one player. Keep players plural after one of, but change have to has: “One of the players has forgotten the kit.”
A later relative clause needs its own agreement check. In “She is one of the students who work here,” who refers to students, so work is plural. The main verb is still agrees with she. “One of” is not a command to make every later verb singular.
And, either...or, neither...nor and not only...but also
Two separate subjects joined by and usually take a plural verb: “Riya and Aman are ready.” If the expression refers to one person or one combined idea, singular agreement can be appropriate: “My friend and guide is here” can describe one person with both roles. Meaning matters.
With either...or and neither...nor, formal agreement commonly follows the subject nearer the verb. “Either the teacher or the students are presenting” uses are because students is nearer. “Either the students or the teacher is presenting” uses is.
The same proximity pattern is commonly taught for subjects joined by not only...but also. “Not only the analyst but also the reviewers were responsible” uses were with the nearer plural subject reviewers. These pairings also need balanced structure, explained later.
Example: Correct “Neither the players nor the coach are available.”
The nearer subject is the coach, which is singular. Write “Neither the players nor the coach is available.” When writing freely, recasting a mixed-number subject can avoid awkward agreement: “The players are unavailable, and so is the coach.”
Indefinite pronouns and quantity expressions
Use singular verbs with everyone, everybody, someone, anyone and nobody: “Everyone knows the answer.” Formal usage also commonly uses singular agreement with either of and neither of: “Neither of the answers is correct.” Plural agreement with neither of occurs in ordinary usage; follow any explicitly stated formal convention.
Compare a number of and the number of. “A number of students are absent” means several students. “The number of absent students is small” talks about one numerical total. The words look similar, but their subjects mean different things.
With proportions and amounts, consider what is being measured: “Half of the cake is left” but “Half of the students are absent.” Similarly, “Ten kilometres is a long distance” treats ten kilometres as one total distance.
Example: Correct “The number of applicants have increased.”
The subject is the numerical total, the number. Change have to has: “The number of applicants has increased.” The plural applicants belongs inside the description of that number.
Collective nouns and there is/there are
A collective noun names a group, such as team, committee or family. Singular agreement treats it as a unit: “The committee has reached a decision.” British English also allows plural agreement when focusing on members: “The team are wearing their new shirts.” Do not declare one form universally wrong without considering the variety and meaning.
In sentences beginning with there, find the noun that follows the verb. “There is a problem” and “There are several problems” are the ordinary written patterns. Introductory there does not tell us the number.
Quick check: Correct “The list of selected candidates are on the noticeboard.”
The head is list, not candidates. Write “The list of selected candidates is on the noticeboard.”
7. Verb forms and helping verbs
Base form, past form and past participle
The base form is the dictionary form, such as go, write or play. The past form can stand in a simple past statement: “She went.” A past participle combines with helping verbs in structures such as “She has gone” and “The letter was written.”
For regular verbs, the past and past participle are often identical: play, played, played. For irregular verbs, they may differ: go, went, gone; write, wrote, written; see, saw, seen; take, took, taken; be, was/were, been.
Do not treat “past participle” as another name for “past tense.” “She has went” is incorrect because has needs the participle gone. “She went” is correct because there is no has in that simple past statement.
Example: Correct “He has wrote the answer.”
The helping verb has introduces a perfect structure. It requires the past participle, written. The corrected sentence is “He has written the answer.”
Do, does and did take the base form
Auxiliary verbs, also called helping verbs, work with another verb. Do, does and did help form many questions and negatives. The following main verb stays in its base form because the auxiliary already carries the required tense and agreement.
Compare “She goes” with “She does not go.” The third-person singular marking appears in does, so it is not repeated in goes. Similarly, “He went” becomes “He did not go”; did already marks the past.
Example: Correct “Did she submitted the form?”
Did already makes the question past. Use the base form submit: “Did she submit the form?” Apply the same rule to “She did not submit the form.”
Be and have do different jobs
A form of be plus an -ing form can describe an action in progress: “She is reading.” A form of have plus a past participle forms a perfect structure: “She has read the book.” These helping verbs cannot be exchanged without changing the structure and meaning.
Be and have can also be main verbs: “She is calm” and “She has a bicycle.” Identify their job before applying a pattern. The word has does not require a past participle when it means possession and is followed by a noun.
Example: Correct “The children are play in the garden.”
The intended meaning is an action in progress. Keep are and use the -ing form: “The children are playing in the garden.” If the intended meaning were a habit, “The children play in the garden” would express that different idea.
8. Tenses: connect verb form to time and meaning
A tense helps locate a situation in time. English also uses aspect, which shows whether we view an action as ongoing, completed before a reference point, or extending over a period. School grammar often teaches the combinations as twelve tense forms.
The important decision is the meaning, not merely a time-word match. Tomorrow does not force will: “The train leaves tomorrow” can correctly describe a timetable. Read what the whole clause communicates.
Simple, continuous, perfect and perfect continuous
A simple form presents a habit, state or event without focusing on its progress: “She works here” or “She worked yesterday.” A continuous form uses be + verb-ing to show activity in progress around a reference time: “She is working now.”
A perfect form uses have + past participle to connect an earlier situation to a reference point: “She has finished” connects completion to now. A perfect continuous form uses have + been + verb-ing to focus on activity over a period leading up to that point: “She has been working for two hours.”
These names will appear below, but each choice still comes back to the event's time and meaning.
Present forms
Use the simple present for habits, general truths and many states: “She walks to college” and “He knows the answer.” Use the present continuous, am/is/are + verb-ing, for an activity happening now or a temporary current activity: “She is preparing for an interview this week.”
The present perfect, has/have + past participle, connects a past event or continuing state to the present. “I have lost my key” focuses on the present result. “I have lived here for five years” describes a situation continuing up to now.
The present perfect continuous, has/have been + verb-ing, focuses on ongoing or recent activity and its duration: “She has been practising since morning.” With some verbs, both perfect forms can work, but the emphasis differs: has written three pages stresses a completed amount; has been writing stresses the activity.
Example: Correct “She has completed the assignment yesterday.”
Here yesterday places this completion in a finished past period. In an ordinary statement about that finished event, use the simple past: “She completed the assignment yesterday.” Alternatively, “She has completed the assignment” is correct without that finished-time detail.
Past forms
The simple past describes completed past events and past states: “He called last night.” The past continuous, was/were + verb-ing, describes an action in progress at a past time: “He was cooking when I called.” The cooking was already underway; the call occurred during it.
The past perfect, had + past participle, looks back from a past point to something earlier: “The bus had left when we reached the stop.” The past perfect continuous, had been + verb-ing, highlights activity continuing up to a past point: “They had been waiting for an hour when the bus arrived.”
Example: Choose the intended form: “By the time I reached the hall, the programme ___ already ___.”
The programme started before my arrival, and the sentence looks back from that later past arrival. Use “had already started.” The complete sentence is “By the time I reached the hall, the programme had already started.”
Do not force the past perfect into every sentence with two past events. “I opened the door and walked inside” presents a straightforward sequence; both simple past verbs are correct.
Future forms
Will + base verb can express a prediction or decision: “I will call you.” Be going to + base verb can express an existing plan or a prediction based on present evidence: “She is going to apply for the role.” Present continuous can describe an arrangement: “We are meeting the tutor tomorrow.”
The future continuous, will be + verb-ing, describes activity in progress at a future point: “At nine tomorrow, I will be travelling.” The future perfect, will have + past participle, describes completion by a future point: “By Friday, I will have finished the report.”
The future perfect continuous, will have been + verb-ing, focuses on duration up to a future point: “By June, she will have been working here for three years.” The duration and the future reference point explain the longer verb phrase.
Example: Correct “By next Monday, I will have finish the course.”
Will have is followed by a past participle. Change finish to finished: “By next Monday, I will have finished the course.” The sentence means completion will happen no later than that future reference point.
Since, for and continuing states
Since names a starting point: since Monday, since 2022. For names a duration: for three days, for two years. Choose the preposition from the kind of time expression, then choose the tense from the full meaning.
Example: Correct “She has lived here since five years.”
Five years is a length of time, not a starting point. Write “She has lived here for five years.” We could also say “She has lived here since 2021” if that were the intended starting year.
For does not automatically require a perfect tense. “She lived here for five years before moving away” correctly uses the simple past for a finished period.
Some verbs commonly describe states, such as know, own, believe and belong. In those meanings, simple or perfect forms are usually appropriate: “I know the answer,” not “I am knowing the answer.” A verb can change behaviour when its meaning changes: “I am thinking about the problem” describes a mental activity, whereas “I think it is correct” states an opinion.
Keep time relationships consistent
Consistency means preserving the intended sequence, not making every verb look the same. “I know that she left yesterday” correctly combines a present state of knowledge with a past departure.
In an ordinary future time clause after when, before, after or until, use a present form: “I will call when I arrive.” Do not write “I will call when I will arrive” for that meaning. But “I do not know when he will arrive” is an indirect question about arrival time, so will is appropriate there.
Quick check: Correct “She does not knows where the office is.”
Use know after does not: “She does not know where the office is.” The later is belongs to another clause and remains correct.
9. Modals, infinitives and gerunds
Modals and the verb that follows
Modal verbs add meanings such as ability, possibility, permission or obligation. Common modals include can, could, may, might, will, would, shall, should and must. They are followed by a base-form verb: “She can swim,” “He should study,” “They must leave.”
Do not add -s, -ed or to to the verb immediately after these modals. “She can sings” and “He must to leave” are incorrect. Ought to is a different established pattern, so do not remove its to by applying the core-modal rule mechanically.
Example: Correct “You should to check the answer.”
Should takes the base verb directly. Remove to: “You should check the answer.” This expresses advice about the action of checking.
A modal can be followed by the base form of another helping verb: “She may be working” or “He must have forgotten.” In the second example, have is the base form after must, while forgotten is the participle required by have.
Meaning also matters. Must not expresses prohibition: “You must not enter.” Need not or do not have to expresses lack of necessity: “You need not attend.” These are not interchangeable corrections.
To-infinitives and gerunds
An infinitive uses a base-form verb. A to-infinitive includes to, as in to read. A gerund is an -ing verb form used in a noun-like role, as in “Reading improves vocabulary.” Do not confuse this with “She is reading,” where reading forms part of a continuous verb phrase.
Some verbs are followed by a to-infinitive: decide to leave, hope to win, plan to study. Others are followed by an -ing form: enjoy reading, avoid guessing, finish writing. Learn the verb together with its following pattern.
Example: Correct “She enjoys to read novels.”
For this meaning, enjoy takes an -ing complement. Change to read to reading: “She enjoys reading novels.” The noun novels still tells us what she reads.
Some verbs allow both forms, sometimes with different meanings. “He stopped smoking” means he ended that habit or activity. “He stopped to smoke” means he paused another activity so that he could smoke. Neither is automatically wrong; the surrounding meaning decides.
Actions after prepositions
When a verb directly follows a preposition as its complement, it normally takes the -ing form: after eating, without asking, by practising. This also applies to word combinations such as capable of, interested in and responsible for.
Example: Correct “He is capable to handle the task independently.”
The adjective capable takes of when describing this ability. Because the action handle follows the preposition, use handling: “He is capable of handling the task independently.” Both the preposition and the verb form need to fit the pattern.
The word to can itself be a preposition. In “I look forward to meeting you,” to belongs to look forward to and is followed by meeting. It is different from the infinitive marker in “I want to meet you.” The test “look forward to the meeting” helps show that to introduces a noun-like complement here.
Verb + person + infinitive
Some verbs name a person before a to-infinitive: “She asked me to wait” and “The teacher told us to revise.” Do not transfer this pattern to every verb. Standard patterns include “She suggested waiting” and “She suggested that we wait,” rather than “She suggested me to wait.”
After let and active make, use an object followed by a base verb: “Let him speak” and “The noise made me wake up.” Passive make uses to: “I was made to wait.” Help permits both “help me understand” and “help me to understand.”
Example: Correct “They let us to enter.”
In the pattern let + object + base verb, us is the object and enter is the base verb. Remove to: “They let us enter.”
10. Active and passive voice
In active voice, the subject normally performs the action: “Riya wrote the report.” In passive voice, the subject is the person or thing affected: “The report was written by Riya.” Both can be correct; the choice changes the focus.
The basic passive pattern is a suitable form of be + past participle. The helping verb shows tense and agreement: “The report is checked,” “The reports were checked,” “The report has been checked.” A modal passive uses modal + be + past participle: “The report must be checked.”
Example: Correct “The letters were send yesterday.”
The letters received the action, so the passive structure is appropriate. Were is already plural and past. The required participle of send is sent: “The letters were sent yesterday.”
Do not make a passive merely because a sentence sounds formal. Verbs such as happen and arrive do not normally take an object that can become a passive subject. Write “The accident happened,” not “The accident was happened.”
11. Adjectives, adverbs and comparisons
Describing a noun versus describing an action
An adjective describes a noun or pronoun: “She is careful.” An adverb can describe how an action happens: “She writes carefully.” First decide what the disputed word describes, then choose the form.
Example: Correct “He answered the question confident.”
Confident is intended to describe how he answered. Use the adverb confidently: “He answered the question confidently.” In “He was confident,” the adjective is correct because it describes he through the linking verb was.
Linking verbs such as seem, become, look, feel and taste can take adjectives: “The soup tastes good.” Compare “She tasted the soup carefully,” where carefully describes a deliberate action. The verb's job changes the required description.
Not every adverb ends in -ly
Fast, hard and late can be adverbs without -ly: “She works hard” and “He arrived late.” The related forms may mean something different. Hardly means almost not; lately means recently.
Example: Compare “She works hard” with “She hardly works.”
The first means she puts in effort. The second means she does almost no work. Changing hard to hardly is not a grammatical improvement; it changes the message.
Similarly, friendly is normally an adjective despite its -ly ending. “She spoke in a friendly way” expresses the manner naturally.
Comparative and superlative forms
A comparative compares one person or thing with another: taller, more careful. A superlative identifies an extreme within a group: tallest, most careful. Many short adjectives take -er/-est, while longer ones commonly use more/most.
Some forms are irregular: good/better/best and bad/worse/worst. Do not mark the same comparison twice: more better and most tallest are incorrect in ordinary standard comparisons.
Example: Correct “This method is more easier than that one.”
Easier already carries the comparative meaning. Remove more: “This method is easier than that one.” If you want to express a large difference, “much easier” is correct because much strengthens the comparison rather than forming it again.
Use than for ordinary comparative comparisons and as...as for equality: “She is taller than I am” and “She is as tall as I am.” “She is taller than me” is also accepted usage; do not invent an error solely because the shorter object form appears.
Compare like with like
A comparison must connect the intended things. “The climate of Chennai is warmer than Bengaluru” appears to compare a climate with a city. Write “The climate of Chennai is warmer than that of Bengaluru,” where that stands for the climate.
When comparing one member against the rest of its own group, exclude that member from the other side. “Riya is taller than any other student in her class” avoids comparing Riya with herself. If the groups are different, other may be unnecessary: “Riya is taller than any student in the junior class” can be correct if Riya is not in that class.
Enough, too, so and such
Enough means sufficient. Put it after an adjective or adverb, but before a noun: old enough, quickly enough, enough time. “She is enough tall” should be “She is tall enough.”
Too + adjective + to-infinitive describes an excessive degree that prevents or makes an action unsuitable: “The bag is too heavy to lift.” So + adjective + that-clause gives a degree and its result: “The bag is so heavy that I cannot lift it.”
Example: Correct “The report is too detailed that it confuses new readers.”
The second clause, that it confuses new readers, states a result. Use the so...that pattern: “The report is so detailed that it confuses new readers.” This keeps the intended result and changes only too to so.
Such introduces a noun phrase: “It was such a useful lesson that I took notes.” With a singular countable noun, the order is such + a/an + adjective + noun. These are patterns for particular meanings, not a rule that every occurrence of too must be followed by to: “The room is too warm” is already complete.
12. Prepositions: time, place and word combinations
Time and place relationships
For many time expressions, use at for a point, on for a day or date, and in for a month, year or longer period: at six, on Monday, in July, in 2026. Established expressions include at night and in the morning.
With words such as next, last, this and every, a preposition is often unnecessary: next Monday, last year, every morning. Write “We will meet next Tuesday,” not “We will meet on next Tuesday.”
For place, in often presents an enclosed area, on a surface and at a point or location: in the room, on the desk, at the entrance. Different choices can convey different viewpoints, so they are not always interchangeable errors.
Example: Correct “The interview begins in 10 a.m.”
10 a.m. is a particular clock time. Use at: “The interview begins at 10 a.m.” Do not confuse this with “The interview begins in ten minutes,” which describes how long from now it will begin.
By, until, between and among
By gives a deadline: “Submit the form by Friday” means no later than Friday. Until describes continuation up to a point: “Wait until Friday.” Choose according to whether the action must be completed or must continue.
Example: A report must be completed no later than noon. Correct “Finish the report until noon.”
Completion needs a deadline, so write “Finish the report by noon.” “Work on the report until noon” would be grammatical but would mean continue working up to that time, without necessarily finishing.
Between often presents distinct relationships, while among presents membership or position within a group: between the two buildings, among friends. Between is not restricted to exactly two items; it can describe distinct relationships among several parties, such as an agreement between three companies.
Learn the complete expression
Some prepositions are selected by the preceding word: depend on, belong to, interested in, capable of, responsible for and insist on. Learn these as usable expressions, with a sentence showing their meaning.
Example: Correct “The result depends of your preparation.”
The established expression is depend on. Write “The result depends on your preparation.” The subject result is singular, so depends remains correct.
Other verbs take a direct object without a preposition in the intended pattern: discuss the problem, enter the room, reach the station. Write “We discussed the problem,” not “We discussed about the problem.” However, “We had a discussion about the problem” is correct because the noun discussion uses a different structure.
13. Conjunctions and parallel structure
Join ideas according to their relationship
A conjunction connects words, phrases or clauses. And adds information, but contrasts it, because introduces a reason, and so introduces a result. The connector must fit the meaning.
“Riya studied, so she improved” presents improvement as a result. “Riya studied, but she did not improve” presents an unexpected contrast. Both are grammatical because their connectors match their messages.
In ordinary standard constructions, do not double the link with although...but or because...so. Use “Although it rained, we played” or “It rained, but we played.” Use “Because it rained, we stayed inside” or “It rained, so we stayed inside.”
Example: Correct “Although the task was difficult, but she completed it.”
Although already introduces the contrast. Remove but: “Although the task was difficult, she completed it.” The two clauses now form a complete standard sentence.
Pair the connecting words correctly
Common pairs include either...or, neither...nor, both...and and not only...but also. Check both the pair itself and the grammatical material it connects.
Example: Correct “You can either email the form nor bring a printed copy.”
The sentence offers two alternatives, so either pairs with or. Write “You can either email the form or bring a printed copy.” Both alternatives are actions expressed with base-form verbs after can.
Keep connected elements parallel
Parallel structure means using matching grammatical structures for items serving the same role. In “She enjoys reading, writing and painting,” all three activities use -ing forms. Mixing in to paint breaks the established list structure.
Example: Correct “She is not only intelligent but also works hard.”
The verb is introduces the description intelligent. The words after but also should fit the same structure. Use another adjective: “She is not only intelligent but also hardworking.”
Another repair is “She not only is intelligent but also works hard.” Here the pair connects two verb phrases, is intelligent and works hard. This shows why placement matters. In a segmented question, choose the repair that fits the available segment and preserves the intended meaning.
Parallelism does not mean every nearby word needs an identical ending. “She wants to read and write” is parallel because to can be shared by the two base verbs. “She wants to read and to write” is also correct.
14. Conditionals: real and imagined situations
A conditional sentence connects a condition with its result. The condition often begins with if: “If it rains, we will stay inside.” First decide whether the situation is a general fact, a realistic future possibility, an imagined present situation or an imagined change to the past.
General truths and realistic future possibilities
The zero conditional commonly uses present forms in both clauses for a general relationship: “If you heat ice, it melts.” It describes what generally happens, rather than predicting one particular event.
The first conditional commonly uses if + simple present and will + base verb for a realistic future possibility: “If she studies, she will improve.” Other result forms can fit the meaning: “If you finish early, call me” gives an instruction.
Example: Correct “If he will practise regularly, he will improve,” where the first clause states an ordinary future condition.
Use a present form in that condition clause: “If he practises regularly, he will improve.” The future meaning comes from the relationship between the clauses. This does not mean will can never appear after if; special meanings such as willingness use different patterns.
Imagined present or future situations
The second conditional commonly uses if + past form and would + base verb: “If I had more time, I would learn another language.” The past form expresses distance from reality here; it does not describe a finished past event.
For imagined situations with be, were is the conventional formal choice for all persons: “If I were the team leader, I would change the schedule.” Was also occurs in hypothetical usage, especially less formal English. Use were when the task explicitly expects that formal pattern.
“If I was rude yesterday, I apologise” is different. It expresses uncertainty about a possible past fact, not an imaginary present role. Do not replace every if I was with if I were.
Imagined changes to the past
The third conditional commonly uses if + had + past participle and would have + past participle. Both clauses concern an unreal alternative past: “If I had checked the address, I would have reached the correct building.”
The sentence suggests that I did not check and did not reach the correct building. Had checked imagines a different earlier action; would have reached imagines its past result. Could have and might have can express ability or possibility instead of the more definite would have.
Example: Correct “If she had left earlier yesterday, she would catch the morning bus,” where both the departure and bus journey are past.
The result also belongs to the imagined past. Write “If she had left earlier yesterday, she would have caught the morning bus.” The participle of catch is caught.
Had I known and mixed time relationships
A formal conditional can omit if and put had before the subject: “Had I known” means “If I had known.” The rest of the sentence must still fit the intended time relationship.
Example: Correct “Had I known about yesterday's cancellation, I would inform you before you left.”
Both the missed knowledge and the missed chance to inform you belong to the past. Write “Had I known about yesterday's cancellation, I would have informed you before you left.” The correction follows from the past meaning of the result, not merely from seeing had.
A mixed conditional can connect an unreal past condition to an imagined present result. “If I had accepted that job, I would live in Delhi now” is grammatical: the acceptance belongs to the past, while the imagined residence belongs to now. Do not automatically change would live to would have lived. The British Council explains these mixed time relationships.
Unless and unnecessary negatives
Unless commonly means if not: “Unless you hurry, you will miss the bus” means “If you do not hurry, you will miss the bus.” Adding another negative can reverse the intended condition.
Example: The intended advice is that you must study to pass. Correct “Unless you do not study, you will fail.”
Write “Unless you study, you will fail.” Here the unwanted not changes the condition. This is a meaning-based correction; a negative after unless is not impossible in every other context.
15. Requests, recommendations and special verb forms
The subjunctive after a request or recommendation
A subjunctive is a special verb form used in certain constructions. In a formal request, demand or recommendation followed by a that-clause, the verb can stay in its base form regardless of the subject: “The tutor recommended that she revise the chapter.”
This pattern describes what is wanted, rather than reporting what already happens. Therefore, the ordinary present-agreement ending is absent: she revise, not she revises, in the base-form subjunctive construction. Common introducing verbs include ask, request, recommend, suggest, insist and demand, when used with the relevant meaning.
Example: Rewrite in the base-form subjunctive: “The teacher asked that every student submits the form.”
The sentence expresses a request about submitting. Change submits to the base form submit: “The teacher asked that every student submit the form.” Every student remains singular, but this special construction does not use ordinary present-tense agreement.
The base form of be is simply be: “The manager insisted that the trainee be punctual.” A common accepted alternative, particularly in British English, uses should: “The manager insisted that the trainee should be punctual.” Cambridge includes should in that-clause suggestion patterns.
Active, passive and negative requests
An active request uses the base verb: “They requested that she review the policy.” A passive request uses be + past participle: “They requested that the policy be reviewed.” The policy receives the review, so it is the passive subject.
Example: Express this demand in the base-form subjunctive: “The employees demanded an immediate review of the policy.”
Introduce the requested outcome with that. Make the policy the subject and use the passive base-form structure: “The employees demanded that the policy be reviewed immediately.” “The policy should be reviewed” is another accepted way to express the requested outcome after that.
For a negative base-form subjunctive, put not before the verb: “The tutor requested that students not use calculators.” Do not insert do merely by copying an ordinary negative statement.
Check what insist and suggest mean
The same verb can introduce a report or belief rather than a request. “She insisted that she was innocent” reports a strong assertion about her innocence. “The evidence suggests that the answer is incorrect” means the evidence points to a conclusion. These do not require the request-pattern base form. Cambridge records this meaning of suggest.
Do not memorise “always remove must after demand or insist.” In an exercise specifically asking for the base-form subjunctive, use that construction. In unrestricted English, first establish what the sentence means and which construction it uses; the presence of one introducing verb is not enough to prove an error.
It is time and it is high time
With an explicit subject after it is time, it is about time or it is high time, the usual pattern uses a past verb form for something that should happen now. “It is high time we left” means leaving is due or overdue; it does not say we have already left.
Example: Correct “It is high time the team submits the report.”
The clause after high time has its own subject, the team. Use the past form submitted: “It is high time the team submitted the report.” The meaning remains present urgency.
A different structure uses a to-infinitive: “It is time to leave” or “It is time for us to leave.” Keep leave in its base form there. Cambridge distinguishes these time expressions.
16. Inversion and closely timed events
Helping verb before subject
Inversion changes the usual subject–verb order. In the formal patterns here, an auxiliary comes before the subject after an opening negative or limiting adverbial. Compare “I have never seen this” with “Never have I seen this.”
Words such as seldom, rarely and never can trigger this structure when they begin the clause and limit the event. If an auxiliary already exists, move it: “Seldom have I seen such care.” If there is no auxiliary, use do, does or did, and put the main verb in its base form.
Example: Correct “Rarely she misses a class.”
The ordinary statement is “She rarely misses a class.” Moving rarely to the front calls for inversion. Add does before she, then change misses to miss: “Rarely does she miss a class.”
Not every first word with a negative association triggers inversion. “Little children need rest” begins with an adjective describing children, not a limiting adverbial. Its normal word order is correct.
Only after, only when and not until
When an opening expression such as only after or not until limits when the main event happened, inversion occurs in the main clause. The clause inside the opening expression keeps its own normal order.
Example: Correct “Only after the tutor explained the rule I understood it.”
Keep the tutor explained the rule in normal order. Invert the main clause with did I understand: “Only after the tutor explained the rule did I understand it.” The base form understand follows did.
Compare “Only Riya understood the rule.” Here only limits the subject Riya, so the sentence does not need inversion.
Hardly, scarcely and no sooner
These expressions can show that one event happened almost immediately before another. Common patterns are Hardly/Scarcely had + subject + past participle + when + past clause and No sooner had + subject + past participle + than + past clause.
Example: Correct “Hardly had the meeting started than the lights went out.”
The sentence uses the hardly...when sequence. Replace than with when: “Hardly had the meeting started when the lights went out.” The first event is the start of the meeting; the second follows almost immediately.
Similarly, “Scarcely had she sat down when the bell rang” and “No sooner had she sat down than the bell rang” are correct. Notice the inverted had she in both sentences.
Before is also possible with hardly/scarcely in suitable sentences, so “only when is ever grammatical” would be too strong. The useful distinction is that than belongs to no sooner in this comparison pattern. Oxford explains hardly, scarcely, barely and no sooner.
17. Modifiers and clear sentence attachment
A modifier adds description or limits meaning. Adjectives, adverbs, phrases and clauses can all modify other parts of a sentence. Place them so that the intended connection is clear.
Opening action phrases need the right subject
In “Walking to college, Riya found a wallet,” the opening phrase describes Riya. If the following subject cannot logically perform the opening action, the modifier dangles: “Walking to college, a wallet was found by Riya” appears to make the wallet the walker.
Example: Correct “Walking through the corridor, the broken window was noticed by me.”
The person walking was I, not the broken window. Put the walker in the main subject position: “Walking through the corridor, I noticed the broken window.” Another repair gives the opening clause its own subject: “While I was walking through the corridor, I noticed the broken window.”
This check is especially useful for ordinary opening participial phrases without an expressed subject. Some established expressions, such as generally speaking, work differently; do not treat every opening phrase as an identical structure.
Give a reason its own subject when needed
Example: Correct “Being a rainy day, the match was postponed.”
The main subject is the match, which cannot be a rainy day. Replace the opening phrase with a clause that has an appropriate subject: “As it was a rainy day, the match was postponed.” The passive was postponed remains correct.
“It being a rainy day, the match was postponed” is also grammatical because the opening construction now has its own subject, it. The full as-clause is usually easier for a beginner to follow.
Placement can change meaning without creating an error
Compare “Only Riya borrowed the book” with “Riya borrowed only the book.” The first excludes other borrowers; the second excludes other borrowed items. Both are grammatical, but they answer different questions.
Do not label every change in word order as a correction. In an error-spotting task, preserve the intended meaning and identify an actual problem with the construction or its attachment.
18. Reported speech and indirect questions
Direct speech gives a person's words: Riya said, “I am tired.” Reported speech reports the message: “Riya said that she was tired.” Pronouns and time expressions may change because the reporter's viewpoint differs from the speaker's.
After a past reporting verb, a shift to a past form is common: am becomes was, have finished becomes had finished, and will becomes would. This shift is called backshift. It is not automatic when the fact remains true or the report keeps the original time viewpoint.
“Riya said that she lives in Chennai” can be correct if she still lives there. Similarly, replace today with that day only when the reporting context requires that change. Meaning controls the transformation.
Indirect questions use statement order
A direct question uses “Where is the office?” Inside an indirect question, use subject before verb: “She asked where the office was.” Do not keep direct-question inversion inside the embedded clause.
Example: Correct “He asked me where was the library.”
The embedded subject is the library. Put it before was: “He asked me where the library was.” The main clause He asked me remains unchanged.
For yes/no questions, use if or whether: “She asked whether I was ready.” For a reported instruction, use tell/ask + person + to-infinitive: “She told me to wait.” These structures build on the clause and infinitive patterns already explained.
19. Apply the rules to a complete question
A long sentence may contain several clues, but a clue is useful only when it belongs to the structure being checked. Use the following routine as an order of attention, not as a guarantee that every error will appear in a fixed place.
- Read the full sentence for meaning. Decide who or what it is about, what happens and when.
- Find the main clauses and their subjects and verbs. Temporarily bracket extra descriptions if they hide the sentence skeleton.
- Check agreement and verb structure. Look at auxiliaries, participles, modals and the time relationship.
- Check noun phrases and word combinations. Examine articles, quantity words, pronouns and prepositions.
- Check connections. Review comparisons, conjunction pairs, parallel items, conditionals and opening modifiers.
- Make the smallest justified correction and reread. Confirm that it fixes the sentence without changing the intended message. Then select the segment containing that correction.
Case 1: A distant subject controls the verb
Example: Identify the error: (A) The quality of these notebooks / (B) have improved / (C) considerably / (D) this year.
The sentence describes the quality, which is singular. Of these notebooks tells us whose quality is being discussed. Therefore, the perfect helping verb should be has. The answer is B, and the corrected sentence is “The quality of these notebooks has improved considerably this year.”
The time expression this year can include the present, so the present perfect is appropriate. There is no need to change it to a simple past form merely because improvement began earlier.
Case 2: The preposition controls the following action form
Example: Identify the error: (A) She is responsible / (B) for prepare / (C) the weekly report / (D) for the team.
The combination responsible for is correct. The problem is the base verb prepare directly after the preposition. Use preparing, giving “She is responsible for preparing the weekly report for the team.” The answer is B.
Case 3: The required construction overrides ordinary agreement
Example: Choose the correction that uses the base-form subjunctive: “The tutor recommended that Riya revises the chapter.”
In an ordinary statement, “Riya revises the chapter” is correct. Here, however, the instruction explicitly asks for a recommendation in the base-form subjunctive. Use “The tutor recommended that Riya revise the chapter.” The construction explains why the singular subject does not take revises.
Case 4: No error is a valid result
Example: Identify the error, or choose E for No error: (A) One of the students / (B) has volunteered / (C) to organise / (D) the event.
One takes has. The participle volunteered fits after has, and volunteered to organise is a correct verb pattern. The noun phrase the event is also grammatical. Choose E: No error.
Do not change students to student. The plural group after one of is required even though the main subject is singular.
20. Mixed practice with explained answers
For each question, identify the incorrect segment, A–D. Choose E: No error if the sentence is grammatical. Each item has either one segment to correct or no error; the answer explanations follow the complete set.
- (A) The children / (B) was playing / (C) outside / (D) after lunch.
- (A) She bought / (B) an useful dictionary / (C) for her brother / (D) yesterday.
- (A) The tutor gave us / (B) several useful advices / (C) before / (D) the interview.
- (A) The manager thanked / (B) Riya and I / (C) for completing / (D) the report.
- (A) Every member / (B) have received / (C) a copy / (D) of the schedule.
- (A) The list of participants / (B) is displayed / (C) near / (D) the entrance.
- (A) Did you / (B) checked / (C) the address / (D) before leaving?
- (A) She has / (B) wrote / (C) three pages / (D) so far.
- (A) We / (B) can to discuss / (C) the proposal / (D) tomorrow.
- (A) He has worked here / (B) since five years / (C) and knows / (D) the process well.
- (A) The invitation / (B) was send / (C) to all members / (D) last week.
- (A) She answered / (B) every question / (C) confident / (D) during the interview.
- (A) This route / (B) is more shorter / (C) than the road / (D) through the village.
- (A) They are capable / (B) of solving / (C) the problem / (D) without help.
- (A) Although the hall was full, / (B) but the staff / (C) found a seat / (D) for the visitor.
- (A) The course teaches / (B) reading, writing / (C) and to speak / (D) clearly.
- (A) If she had checked yesterday's timetable, / (B) she would have catch / (C) the earlier train / (D) yesterday morning.
- (A) It is high time / (B) we leave / (C) for / (D) the station.
- (A) Seldom / (B) I have seen / (C) such a neat / (D) notebook.
- (A) Hardly had we sat down / (B) than / (C) the bell / (D) rang.
- (A) Being a rainy day, / (B) the outdoor class / (C) was cancelled / (D) by the teacher.
- (A) The student / (B) who solved the puzzle / (C) received / (D) a prize.
- (A) She asked me / (B) where was the office / (C) and whether / (D) it was open.
- (A) The report was so clear / (B) that everyone / (C) understood / (D) the conclusion.
Answer key
1. B: was playing → were playing. Children is plural, so the helping verb must be were. The corrected sentence is “The children were playing outside after lunch.” The -ing form already fits the past continuous structure.
2. B: an useful dictionary → a useful dictionary. Useful begins with a consonant-like “y” sound. Write “She bought a useful dictionary for her brother yesterday.” The choice follows sound, not the vowel letter u.
3. B: several useful advices → several useful pieces of advice. Advice is uncountable in this meaning. Count pieces instead: “The tutor gave us several useful pieces of advice before the interview.”
4. B: Riya and I → Riya and me. The people thanked form the object of thanked. Write “The manager thanked Riya and me for completing the report.” Removing Riya and temporarily gives the helpful check “thanked me.”
5. B: have received → has received. Every member is singular. Write “Every member has received a copy of the schedule.” The participle received does not change.
6. E: No error. The subject's head is list, so is displayed is correct. The complete sentence, “The list of participants is displayed near the entrance,” is grammatical. Participants does not control the verb.
7. B: checked → check. The auxiliary did already marks past time. Write “Did you check the address before leaving?” The main verb after it must be the base form.
8. B: wrote → written. Has requires the past participle in this perfect structure. Write “She has written three pages so far.” The simple past form wrote cannot fill that position.
9. B: can to discuss → can discuss. Can takes the base verb directly. The corrected sentence is “We can discuss the proposal tomorrow.” No preposition is needed before the object the proposal either.
10. B: since five years → for five years. Five years expresses duration. Write “He has worked here for five years and knows the process well.” Since would need a starting point.
11. B: was send → was sent. The invitation receives the action, so a passive is appropriate. Write “The invitation was sent to all members last week,” using the participle sent.
12. C: confident → confidently. The disputed word describes how she answered, so it needs the adverb form. Write “She answered every question confidently during the interview.”
13. B: is more shorter → is shorter. Shorter already forms the comparative. Write “This route is shorter than the road through the village.” The extra more repeats the comparative marking.
14. E: No error. Capable of solving correctly combines the adjective, preposition and -ing form. “They are capable of solving the problem without help” needs no correction.
15. B: but the staff → the staff. The opening although already expresses the contrast. Write “Although the hall was full, the staff found a seat for the visitor.”
16. C: and to speak → and speaking. The course teaches three activities in a parallel list. Write “The course teaches reading, writing and speaking clearly.” All three activity names now use -ing forms.
17. B: she would have catch → she would have caught. The imagined result belongs to the past, and have requires a participle. Write “If she had checked yesterday's timetable, she would have caught the earlier train yesterday morning.”
18. B: we leave → we left. In It is high time + subject + verb, the usual verb form is past despite the present meaning. Write “It is high time we left for the station.”
19. B: I have seen → have I seen. Opening seldom triggers inversion in this construction. Write “Seldom have I seen such a neat notebook.” Move the existing auxiliary have before I.
20. B: than → when. This sentence uses the hardly...when pattern. Write “Hardly had we sat down when the bell rang.” The inverted order and participle sat are already correct.
21. A: Being a rainy day → As it was a rainy day. The outdoor class cannot be a rainy day. Give the reason clause its own subject: “As it was a rainy day, the outdoor class was cancelled by the teacher.”
22. E: No error. Who is the subject of solved, so it is the correct relative pronoun. “The student who solved the puzzle received a prize” is grammatical.
23. B: where was the office → where the office was. An indirect question takes statement order. Write “She asked me where the office was and whether it was open.” The second embedded clause already has the correct order.
24. E: No error. So clear that correctly introduces a result clause. “The report was so clear that everyone understood the conclusion” needs no change.
21. Common mistakes to avoid
Choosing the nearest noun as the subject. In “The quality of the answers is good,” quality controls is. Use proximity only in a construction where that agreement pattern applies, such as mixed subjects joined by either...or.
Applying an ordinary rule inside a special construction. “She writes” uses ordinary present agreement, but “They requested that she write” uses a base-form subjunctive. Identify the construction before adding or removing an ending.
Using a time word as an automatic tense command. For can occur with a finished past period, and tomorrow can occur with a present timetable form. The event's meaning and reference time must support the choice.
Treating every alternative as an error. Object who, singular they, some collective-noun agreement choices and different valid conditional time relationships require attention to usage and meaning. A sentence can be correct even when a different form is more formal.
Correcting the clue instead of the error. In “One of the students have arrived,” students supplies part of the subject description, but have needs repair. Select the segment containing the faulty word.
Making several unnecessary changes. A correction should solve the identified problem and preserve the message. If a supposedly single-error item needs changes in multiple segments, reread carefully; the item itself may be ambiguous or poorly constructed.
Adding a negative where the meaning is already negative. Standard patterns include “I did not see anyone” and “I saw nobody.” Avoid “I did not see nobody” when the intended meaning is a single ordinary negative. Likewise, hardly already has a near-negative meaning: “I hardly know anyone.”
FAQs
Do I need to learn grammar before practising spotting errors?
You need enough grammar to explain why a correction works, but you can learn and practise together. Read one section, solve its examples, and check the explanation. Move to mixed practice once you can identify subjects, verb forms and common word relationships without a topic label.
Which rules should I study first?
Begin with sentence structure, singular/plural nouns, articles, pronouns and subject–verb agreement. Then study verb forms, tenses and common preposition patterns. Conditionals, subjunctives and inversion become easier once those foundations are clear.
Can I solve a sentence only by how it sounds?
Familiarity can help you notice a possible issue, but support the answer with a rule and its condition. An unfamiliar formal structure may be correct, while a familiar repeated mistake may sound natural. Explain what controls the correction before selecting a segment.
Is every long sentence more difficult?
No. A long description may hide a simple subject–verb pair. First reduce the sentence mentally to its main clauses, then restore the descriptions and check their connections. Length alone does not determine the grammar involved.
Should I always choose the most formal alternative?
No. If the task asks for a grammatical error, a less formal but accepted form is not automatically wrong. Apply a particular formal convention when the instructions require it, and distinguish that convention from a universal rule.
What should I do when two corrections seem possible?
Check whether both preserve the intended meaning and whether either requires changing another segment. Some sentences genuinely allow more than one repair. In a well-designed single-error question, the instructions and segmentation should make the intended answer clear.
How should I revise after getting a question wrong?
Record the original sentence, the corrected sentence and one sentence explaining the rule. Then write a new example using the same pattern and a contrasting example where the rule does not apply. For instance, compare “One of the students has arrived” with “The students have arrived.”