Spotting Errors is one of the most predictable sections in CDS English — and that is exactly why so many candidates lose marks on it. The question structure is fixed: a sentence is divided into three or four labelled parts, and you pick the part that violates a grammar rule. Option D is almost always "No error."
Think of it like a medical diagnosis. A doctor does not read the whole body at once — she checks known problem zones first: the chest, the BP, the pulse. You do the same with a sentence. You do not read it for meaning and hope an error jumps out. You run the sentence through a checklist of high-yield fault lines, in order, and stop the moment one triggers.
Here is the analogy that works best in the exam hall: treat every sentence like a legal contract. In a contract, every word has a defined role, and even one wrong word makes the whole clause invalid. You are the editor checking before it goes to court. Your job is not to understand the contract — it is to catch the one illegal clause.
The grammar rules tested in CDS Spotting Errors cluster into a handful of categories. Knowing the categories is more important than memorising individual rules, because the exam keeps recycling the same fault lines. The main categories are:
either...or, neither...nor, collective nouns, the number of vs. a number of, and nouns that look plural but are singular (news, data in formal usage, mathematics, physics).If I were...), the past perfect in reported speech, and misuse of would in conditional clauses.despite not despite of, consist of not consist with).inform, remind, tell) being used without one.Once you know these five categories, you are looking at a finite rule set. The exam cannot surprise you — it can only present the same rules in new clothing.
Rule 1: The Proximity Rule for either...or / neither...nor
When two subjects are joined by either...or or neither...nor, the verb agrees with the subject closest to it — not with the first subject, not with the "more important" subject. The subject immediately before the verb controls the verb form.
Either the officers or the soldier is responsible. (singular soldier is closer — singular verb is)Either the soldier or the officers are responsible. (plural officers is closer — plural verb are)This is the Proximity Rule, and CDS uses it in almost every paper. If the sentence has either...or and both subjects differ in number, the answer is almost certainly the part containing the verb.
Rule 2: The number of vs. A number of
This is a classic CDS trap:
The number of + plural noun → singular verb (The number of errors has increased.)A number of + plural noun → plural verb (A number of errors have been found.)The logic: The number refers to a specific count — it is itself the subject, and it is singular. A number of is a quantifier meaning "many" — the real subject is the plural noun it qualifies.
Rule 3: Collective Nouns
In Indian English exams (and formal British English, which CDS follows), collective nouns like committee, jury, government, team, staff take a singular verb when the group acts as a unit.
The committee has decided.The committee have decided. (unless the exam context clearly implies members acting individually — which CDS questions never do)Rule 4: Uncountable and "False Plural" Nouns
Several nouns that appear plural are grammatically singular and always take a singular verb:
news — The news was shocking. (never were)mathematics, physics, economics — singularfurniture, luggage, equipment, information — uncountable, always singulardata — formally plural (plural of datum), but CDS has tested both; the formal rule is data are / data showHypothetical Conditionals
In if-clauses expressing a condition that is contrary to fact or hypothetical, use were for all persons — not was.
If I were in your position, I would act differently.If I was in your position...This applies to first, second, and third person. The moment you see If I/he/she was, that part is almost certainly the error.
Reported Speech Sequence
When the reporting verb is in the past (said, told, informed), the verb in the reported clause shifts back one tense. CDS tests this occasionally but the subjunctive trap is far more frequent.
A small number of preposition errors recur constantly in CDS:
| Incorrect | Correct |
|---|---|
| Despite of | Despite (no of) |
| In spite of | Correct as-is |
| Consist of | Correct — never consist with |
| Married with | Married to |
| Comply to | Comply with |
| Compare with/to | with for similar things, to for dissimilar — but both are increasingly accepted |
The Despite of trap is the single most frequent preposition error in CDS. The rule is simple: despite and of cannot co-exist. Despite already contains the sense of in spite of, so adding of is redundant and wrong.
Certain verbs are transitive — they require an object (a person to receive the action). In CDS, inform is the most frequently tested:
The officer informed that...The officer informed us that... or The officer said that...Other verbs in this category: tell, remind, convince, assure. Any time you see one of these without a human object between the verb and that, the error is in that part.
Do not reflexively reject "No error." CDS papers include genuine no-error sentences to punish over-correction. If you have scanned all five fault zones and found nothing, choose "No error" confidently. Candidates who mark errors on grammatically correct sentences because they "feel" something is off are losing marks on the easiest questions on the paper.
For either...or / neither...nor, draw a mental arrow from the verb backward to the nearest subject. The verb must match that nearest subject — ignore what comes before or/nor. Standard approach (re-reading entire sentence to "sense" the agreement): 30–40 seconds. With the proximity arrow: under 10 seconds. As soon as you see either/neither in any part, immediately locate the verb and check only the immediately preceding subject. That is the only comparison you need.
Print these two sentences in your memory:
THE number of applicants HAS risen. (THE = singular = HAS)A number of applicants HAVE risen. (A = many = HAVE)The capital letters are the anchor. Standard method (re-deriving the rule each time): 20 seconds. With the memorised pair: 5 seconds — you just match the sentence structure to one of your two anchors. No derivation needed.
Four of the most recycled CDS Spotting Errors collapse into one acronym: Were (not was in hypotheticals), Is/has for the number of, Despite (not despite of), Inform needs an object. Before reading any options, scan the sentence for these four triggers. If any appear, that part is your prime suspect. This reduces the options you need to evaluate from four to one in most questions — saving 15–20 seconds per question.
When you see a collective noun (committee, jury, team, government), ask one binary question: Is the group acting as a single unit? In CDS English questions, the answer is always yes. So the verb is always singular (has, was, decides). If the sentence uses a plural verb with a collective noun, the error is confirmed in 3 seconds — no further analysis needed. This shaves approximately 25 seconds off standard subject-identification analysis.
Build a short mental alarm list: news, information, furniture, luggage, equipment, mathematics, physics, economics. The moment any of these appears as the subject, the correct verb is singular. If the sentence pairs any of these with were, have been, are, that is your error — confirmed without parsing the rest of the sentence. Standard parsing time: 30 seconds. Alarm-list match: 5 seconds.
When the clock is running, use this decision tree — in order. Stop as soon as one check fires.
Step 1 — Scan for conjunction: Does the sentence contain either...or or neither...nor? If yes, check the verb against the nearest subject (proximity rule). If mismatch, mark that part.
Step 2 — Scan for the number of / a number of: If present, check whether the verb is singular (has) for the number of or plural (have) for a number of. If wrong, mark it.
Step 3 — Scan for collective nouns: If present (committee, jury, etc.), verb must be singular. If plural verb is used, mark it.
Step 4 — Scan for hypothetical if: If the if-clause contains was, it should be were. Mark it.
Step 5 — Scan for despite of / transitive verb without object: Check for despite of (error: drop of) and for informed that without an object (error: needs informed us that).
Step 6 — Scan for uncountable nouns as subjects: If news, information, etc. is the subject and paired with a plural verb, mark it.
If none of these six checks fires — choose "No error." Do not invent an error.
Total time for this framework on a clean question: 20–35 seconds.
Why this question: This is the single most tested structure in CDS English — the proximity rule with either...or. Getting this wrong costs you a mark and reveals a fundamental gap in subject-verb agreement.
Solving path: Step 1 fires immediately — either...or is present. The subject closest to the verb is my friend (singular). The verb is are coming (plural). Mismatch. Mark part (c). Time: 8 seconds.
Why this question: The number of vs. a number of is a trap that appears almost every year in one form or another. This question tests whether you have internalised the rule or are just guessing from "feel."
Solving path: Step 2 fires — The number of is the subject. The correct verb is singular: has increased, not have increased. The error is in part (c). Time: 10 seconds.
Why this question: The If I was trap catches candidates who know grammar theory but do not apply it under time pressure. The hypothetical subjunctive is a rule with zero exceptions in formal English.
Solving path: Step 4 fires — If I was is present. In a hypothetical contrary-to-fact condition, was must be were for all persons. The error is in part (a). Time: 7 seconds.
Why this question: The transitive verb error (informed that without an object) is subtle because the sentence sounds natural in casual speech. CDS English tests formal written grammar, not conversational usage.
Solving path: Step 5 fires — informed that appears without a human object between informed and that. The verb inform requires an object. Correct form: informed us that. Error in part (a). Time: 12 seconds.
Why this question: This question tests the Despite of trap — a preposition error that appears in CDS with regularity. Candidates who have never consciously noted that despite never takes of will miss this every time.
Solving path: Step 5 fires — Despite of is present in part (A). Despite never takes of. The correct form is simply Despite working hard.... Error in part (A). Time: 6 seconds.
Why this question: News is one of those words that looks and sounds plural but is grammatically singular in English. This trips up candidates at every level — including those who otherwise have strong grammar.
Solving path: Step 6 fires — news is the head noun of the subject phrase. It is uncountable and always singular. The verb were received is plural — this is the error. Correct: was received. Error in part (C). Time: 8 seconds.
Marking "No error" too quickly when a collective noun has a plural verb. Many candidates assume that committee have decided is acceptable British English and mark No error. In CDS, treat collective nouns as singular unless told otherwise. Do not overcorrect toward British colloquial usage.
Confusing either...or with both...and. With both...and, the verb is always plural (Both my brother and my friend are coming.). With either...or, you apply proximity. Mixing up these two constructions is a consistent source of wrong answers.
Applying the proximity rule to not only...but also. The proximity rule applies to either...or and neither...nor. For not only...but also, the same proximity logic applies, but many candidates forget it applies here too. If the closest subject before the verb is singular, the verb is singular.
Assuming data always takes a singular verb. Formally, data is plural (data show, data were collected). CDS questions that test data are testing the formal rule. Do not apply conversational usage (data is) in the exam.
Missing the missing object on inform. The error in The officer informed that... is invisible to candidates who read for meaning rather than structure. Train yourself to pause at informed/told/reminded and ask: who is the object? If there is no object, the error is right there.
Over-reading sentences to find errors that do not exist. Spending 45+ seconds on a "No error" question because you are unsure is a time-drain. If your six-step framework finds nothing, trust the framework. Mark No error and move on.