Grammar Tool — 19 Topics · 570 Questions.

The most tested uncountable nouns in CAT: advice, information, furniture, luggage, equipment, news, knowledge, progress, research, evidence. These NEVER take a/an or a plural form. 'He gave me an advice' is always wrong.

Collective noun trap: strip the sentence to its subject. 'The quality of the answers IS poor' — subject is quality (singular). The phrase 'of the answers' is irrelevant. Find the real noun first.

Uncountable nouns that look plural but are singular: news, mathematics, physics, economics, politics, athletics, billiards. 'The news IS good' — not 'are good'.

The who/whom test is foolproof. Mentally rewrite as a statement. Substitute 'he' or 'him'. 'He' fits → who. 'Him' fits → whom. 'Who/Whom did you invite?' → 'You invited him' → Whom did you invite.

Reflexive pronouns used as polite substitutes for 'me' are always wrong. '✗ Please contact myself' — the subject isn't contacting itself. '✗ Between you and myself' — use me. Reflexive = same person as subject, or for emphasis only.

After prepositions, always use object pronouns. 'Between you and me' (not I). 'For him and her' (not he and she). 'To whom' (not who). The preposition demands an object.

Ambiguous pronoun reference is a major CAT sentence correction error. 'She told her mother that she was wrong' — who was wrong? Rewrite to make the reference clear: 'She told her mother, I was wrong' or 'She admitted to her mother that she herself was wrong.'

The linking verb trap: after look, feel, smell, taste, sound, seem, appear, become, remain — the word that follows describes the SUBJECT (adjective). Test: replace with 'is'. 'She looks is beautiful' → works → adjective. 'She sings is beautifully' → doesn't work → sings is an action verb → adverb needed.

State verbs in continuous tense is a classic error. 'I am knowing', 'She is loving', 'He is wanting' — all wrong. State verbs express conditions that do not change moment to moment. The simple tense is always used: 'I know', 'She loves', 'He wants'.

'Must' has two distinct uses: obligation ('You must submit by Friday') and logical deduction ('She must be tired — she worked 12 hours'). In questions and negatives, 'must' behaves differently: 'Must I?' (obligation) vs 'Mustn't' (prohibition, not just lack of obligation). 'You needn't come' ≠ 'You mustn't come'.

Past Perfect is the #1 tested tense. Rule: whenever two past events appear, the earlier one gets had + V3. Spot the sequence: which happened first? That gets Past Perfect. 'By the time she arrived, he had left' — he left first → had left.

Present Perfect + specific past time = ALWAYS WRONG. No exceptions. If you see 'yesterday', 'last year', 'in 1990', 'an hour ago', 'when I was young' — it must be Simple Past. 'I have seen him yesterday' is impossible in English.

JANES shortcut for Present Perfect: Just, Already, Never/Ever, Since/For. See any of these → Present Perfect is almost certainly correct. Exception: 'for' can also appear with Past Perfect Continuous: 'He had been waiting for two hours.'

No Sooner…Than and Hardly…When both require Past Perfect + inversion. 'No sooner HAD she entered THAN it rained.' 'Hardly HAD he sat down WHEN the phone rang.' Both clauses have inverted word order after 'no sooner' and 'hardly'.

The intervening phrase trap: bracket everything between subject and verb, then check agreement. 'The quality [of the answers] IS poor.' 'The list [of items required] IS ready.' The bracketed phrase is irrelevant to the verb.

A number of vs The number of: 'A number of' means 'several' and takes a plural verb. 'The number of' refers to a specific count and takes a singular verb. 'A number of students ARE absent.' 'The number of students IS increasing.' One article difference — two different agreements.

The one-of-those-who trap: 'She is one of those writers who write from experience' — 'who' refers to 'those writers' (plural) → write. 'She is the only one of those writers who writes from experience' — 'who' refers to 'the only one' (singular) → writes. One word ('only') changes the agreement.

More than one paradox: 'More than one student HAS failed' — despite the plural meaning, 'more than one + singular noun' always takes a singular verb. This is a fixed rule that contradicts intuition.

The a/an SOUND rule catches most test-takers. These always trip people: 'an MBA' (em), 'an NGO' (en), 'an FIR' (ef), 'an X-ray' (ex), 'an honest man' (silent h), 'an hour' (silent h), 'a university' (yoo), 'a European' (yoo), 'a unique opportunity' (yoo), 'a one-time offer' (wun). Say it aloud — that settles it.

Zero article with abstract nouns in general statements is a major trap. 'Life is beautiful' (no article). 'Knowledge is power' (no article). When the abstract noun is used specifically, 'the' is needed: 'The life he lived was remarkable.' Test: can you add 'in general' after it? If yes — no article.

Geographical article rules: THE with rivers (the Nile), mountain RANGES (the Alps), oceans (the Atlantic), island GROUPS (the Maldives), deserts (the Sahara), canals (the Suez Canal). NO THE with individual mountains (Mount Everest), individual islands (Sri Lanka), continents (Asia), most countries (India).

'The + adjective' = a class of people, always plural in meaning: 'The rich ARE not always happy' — not 'is'. The adjective functions as a plural noun.

Double comparative trap: 'more smarter', 'more faster', 'most tallest' — always wrong. If the word already has -er or -est, never add more/most. One form only, never both.

The 'other' rule in comparisons: when you are part of the group you are comparing yourself to, you must use 'other'. 'She is taller than any student' — if she IS a student, this says she is taller than herself. Fix: 'taller than any OTHER student'.

Like-for-like comparison: you must compare the same types of things. 'India's population is greater than China' — wrong, comparing a population to a country. Fix: 'greater than China's (population)' or 'greater than that of China'.

Adjective order is tested subtly. Opinion adjectives (lovely, beautiful, horrible) always come first. Material adjectives (wooden, silver, cotton) always come just before the noun. Age before colour: 'an old red car' not 'a red old car'.

Hard vs Hardly is the most dangerous pair. 'He worked hard' means he put in great effort. 'He hardly worked' means he did almost no work — the OPPOSITE meaning. These two words are antonyms despite looking similar.

Good vs Well: 'He did good' is almost always wrong in standard English. 'Did' is an action verb → adverb 'well' is needed. Exception: 'He did good' can mean 'he performed charitable acts' — a completely different meaning. In exams, 'He did well' is always the correct answer.

Placement of 'only': the position of 'only' changes meaning entirely. 'Only she eats meat' (no one else does). 'She only eats meat' (she does nothing else with it). 'She eats only meat' (no other food). In CAT sentence correction, the misplaced 'only' is a classic error type.

Negative adverbs (hardly, scarcely, never, seldom, rarely, no sooner) at the start of a sentence trigger subject-auxiliary inversion. 'Hardly had she entered when it rained.' 'Never have I seen such bravery.' The inversion is mandatory.

The most tested preposition errors in CAT: (1) 'discuss about' — always wrong, 'discuss' takes no preposition. (2) 'emphasise on' — always wrong. (3) 'reach to' — always wrong. (4) 'married with' — always wrong, use 'married to'.

At/In/On for time: AT for precise times (at 9 am, at noon, at night). ON for days and dates (on Monday, on 15 March). IN for months, years, seasons, longer periods (in March, in 2025, in the morning). These three are tested constantly.

Between vs Among: Between = exactly two items or two specific groups. Among = three or more unspecified items. 'Between you and me' (two people). 'Among the students' (many students). 'Between India, Pakistan, and China' is also correct when referring to defined separate entities.

Fixed preposition pairs: preferable TO (not than), independent OF (not from), differ FROM (things) but differ WITH (people/opinions), comply WITH, abide BY, responsible FOR, married TO, interested IN. Memorise these — they appear in every major exam.

The although…but trap is one of the most frequently tested errors. 'Although' and 'but' are both contrast words — using both is redundant. Similarly 'because' and 'so' cannot both appear. One cause-effect or contrast word per clause only.

Unless means 'if not' — it already contains the negative. 'Unless you don't come' = 'If you don't not come' = 'If you come' — the double negative creates the opposite meaning. Always: 'Unless you come' (not 'unless you don't come').

Correlative conjunction parallel structure: the word that follows 'not only' and the word that follows 'but also' must be the same grammatical form. 'Not only ADJECTIVE but also ADJECTIVE'. 'Not only VERB but also VERB'. The most common error: mixing an adjective with a verb phrase.

So…that vs Such…that: 'So' is used before adjectives and adverbs. 'Such' is used before nouns. 'She was SO tired THAT she fell asleep.' 'It was SUCH a tiring day THAT she fell asleep.' The pattern: so + adjective/adverb + that; such + (a/an) + noun + that.

The passive voice is not wrong — unnecessary passive is weak. In sentence correction, when the active voice expresses the same meaning more directly, the active is preferred. The test: does the passive add any useful emphasis or conceal a genuinely unknown agent? If not, prefer active.

Double object verbs (give, send, offer, show, tell, teach, lend, promise) can form two passive constructions. 'She gave him a book' → 'He was given a book' (more natural) OR 'A book was given to him' (both correct). The first is more common in spoken English.

Modal passives: modal + be + V3. 'You must complete the form' → 'The form must be completed.' 'They should announce the results' → 'The results should be announced.' Never 'must been' or 'should been' — always 'must be', 'should be'.

Continuous passive uses 'being': 'is being written', 'was being discussed'. This is frequently confused with the perfect passive ('has been written', 'had been discussed'). Continuous passive = ongoing right now. Perfect passive = completed with present relevance.

The most common narration error: keeping question word order in reported questions. 'She asked where WAS I going' is always wrong. Reported questions use STATEMENT word order (no inversion, no auxiliary in question position): 'She asked where I WAS going.'

Backshift does NOT always occur. Universal truths resist backshift: 'He said that the Earth REVOLVES around the Sun' — not 'revolved'. The teacher said that 'two plus two IS four'. Scientific and geographical facts stay in present tense.

Reporting verb choice reveals attitude. 'Said' and 'told' are neutral. 'Admitted', 'conceded', 'acknowledged' = accepted reluctantly. 'Claimed', 'insisted', 'maintained' = said with force. 'Warned', 'cautioned' = threat. Choosing the right reporting verb is tested in CAT RC.

Unless = if not already contains the negative. The word 'unless' in reported speech follows standard backshift. Commands use tell + object + to-infinitive. Requests use ask + object + to-infinitive. The object is MANDATORY: 'He told to go' is always wrong — must be 'He told me to go'.

Fragment identification: a sentence must have a subject + finite verb + complete thought. 'Because she was tired' has a subject (she) and a verb (was) but is NOT a complete thought — it is a subordinate clause. Subordinate clauses beginning with because, although, when, if, since, until CANNOT stand alone.

Comma splice is one of the most common errors in competitive exams. Two complete sentences joined by ONLY a comma is always wrong. Fix options: (1) add a FANBOYS conjunction after the comma, (2) replace the comma with a semicolon, (3) replace the comma with a full stop.

The semicolon rule: a semicolon joins two complete, related independent clauses. If either side of a semicolon cannot stand alone as a complete sentence, the semicolon is wrong. Never use a semicolon before a subordinating conjunction.

Sentence type identification is tested in CAT parajumbles and RC. Complex sentences with subordinate clauses beginning with 'although', 'because', 'since', 'when' signal a dependent idea — look for the main clause to follow or precede. The dependent clause cannot be the entire sentence.

Parallel structure is tested in EVERY sentence correction section. The trigger is always a conjunction or a list. When you see 'and', 'or', 'but', 'not only…but also', 'both…and', 'either…or', 'neither…nor' — immediately check: are the elements on both sides the same grammatical form?

The 'not only…but also' trap: the word that follows 'not only' and the word that follows 'but also' must be the SAME part of speech. 'Not only ADJECTIVE but also ADJECTIVE'. 'Not only VERB but also VERB'. The most common error: mixing an adjective with a verb phrase.

List parallelism: read the list items in isolation to check they all fit the same slot. 'The CEO is intelligent, driven, and has vision' — insert each into the sentence: 'The CEO is intelligent ✓ / is driven ✓ / is has vision ✗'. Fix: 'intelligent, driven, and visionary'.

Parallel structure applies to headlines, bullet points, and titles too. In professional writing, a list of bullet points that starts with verbs must continue with verbs. CAT often tests this through parajumbles where the parallel structure helps identify the correct sequence.

Dangling modifier identification: the implied subject of the opening phrase must match the grammatical subject of the main clause. 'Walking down the street, the trees were beautiful' — trees cannot walk. The opening phrase is dangling. Fix: make the implied subject the actual subject: 'Walking down the street, I noticed the trees were beautiful.'

The 'only' placement rule is the most frequently tested modifier question. 'Only I hit him in the eye' (no one else hit him). 'I only hit him in the eye' (I did nothing else to him). 'I hit only him in the eye' (no one else). 'I hit him only in the eye' (nowhere else). One word, four positions, four meanings.

Participial phrase trap: any phrase beginning with a participle (-ing or -ed form) at the start of a sentence MUST refer to the grammatical subject of the main clause. 'Exhausted from the journey, the bed looked inviting' — the bed was not exhausted. Fix: 'Exhausted from the journey, I found the bed inviting.'

Misplaced modifiers change meaning: 'She almost drove her children to school every day' means she almost never drove them. 'She drove her children to school almost every day' means she usually drove them. These mean the OPPOSITE of each other — and both are grammatically correct. Placement is everything.

The its/it's distinction is tested in almost every grammar exam. Rule without exceptions: 'its' = possessive pronoun (no apostrophe, like 'his' or 'her'). 'it's' = it is OR it has. 'The dog wagged its tail' — possessive. 'It's been raining all day' — it has.

Comma splice is the most common punctuation error. Two complete sentences joined by only a comma is always wrong. Fix: (1) add a FANBOYS conjunction after the comma, (2) replace comma with semicolon, (3) use a full stop.

Semicolon before a conjunctive adverb (however, therefore, moreover, consequently, nevertheless): semicolon BEFORE the clause, comma AFTER the conjunctive adverb. 'She studied; however, she failed.' Not 'She studied, however she failed' (comma splice).

Colon after incomplete clauses is always wrong. 'Her hobbies include: reading' is wrong because 'Her hobbies include' is not a complete clause. 'Her hobbies are: reading' is also wrong. Fix: 'Her hobbies include reading and writing' — no colon needed.

Like-for-like comparison is one of the most consistently tested errors in CAT. The fix is always 'that of' (singular) or 'those of' (plural). 'India's GDP is higher than that of China.' 'The prices in Mumbai are higher than those in Delhi.' Memorise this pattern.

The 'other/else' rule: when you are part of the group you are comparing yourself to, you must exclude yourself. 'She is more talented than any student' — if she IS a student, this is illogical. Fix: 'more talented than any OTHER student'. This appears in almost every sentence correction test.

Different from vs different than: in standard British and formal English, always 'different FROM'. 'Different than' is used in American English only before a clause ('different than expected'). In CAT, 'different from' is always the safe choice.

As…as with pronouns: formally, use subject pronouns after the second 'as'. 'She is as intelligent as he is' (not 'as him'). In informal speech, 'as him' is common, but in formal written English and exams, 'as he' is correct.

Fewer/less is tested constantly. The test: can you count individual units? 'Fewer students' (you count students one by one). 'Less water' (you can't count individual water). Common trap: 'less people' is always wrong — people are countable.

Affect/effect: 90% of the time, affect is the VERB and effect is the NOUN. 'The rain affected the match. The effect was significant.' The rare exceptions (effect as verb, affect as noun) appear in advanced contexts only.

Lie/lay confusion: the past tense of 'lie' (to recline) is 'lay' — which is also the present tense of 'lay' (to place). 'I lay down yesterday' = past of lie. 'I lay the book here' = present of lay. Context is the only guide. The past of 'lay' (to place) is 'laid'.

Redundancy errors are subtler than they appear. Test every adjective/adverb: does the noun/verb already contain that meaning? 'New innovation' — innovation is by definition new. 'Past history' — history is always past. 'End result' — a result is always at the end. Remove the redundant word.

Never choose an answer because it 'sounds better' — choose it because you can NAME the grammar rule that makes it correct and all others wrong. If you cannot name the rule, you are guessing. Build the discipline: error type first, then options.

The 'being' trap: on major competitive exams, answer choices containing 'being' are correct only in very specific passive constructions ('the issue being discussed'). In most sentence correction questions, eliminate 'being' options first and verify only if all others are clearly wrong.

The two-error test: always check that your chosen answer does not introduce a NEW error while fixing the original. A sentence with two errors is worse than the original. Scan the chosen option for the most common secondary errors: SVA, tense, pronoun case.

The conciseness principle: when two options are grammatically equivalent, choose the shorter one. 'Due to the fact that' → 'because'. 'In the event that' → 'if'. 'At this point in time' → 'now'. 'Make a decision' → 'decide'. Wordiness is itself an error in formal writing.