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ECG03 — Verbs & Helping Verbs

📚 Chapter ECG03 · CDS Grammar Level CDS Level

📌 CDS Focus: Verbs and helping verbs together account for the largest share of errors in CDS English — consistently appearing in Spotting Errors, Fill in the Blanks, and Sentence Improvement across every paper. The chapter is built entirely around patterns confirmed in CDS PYQs from 2022–2025. Content that is textbook theory but never tested in CDS has been left out.

PART A — VERBS

1. Subject–Verb Agreement ▲ Single Biggest Error Source in CDS

The Rule: The verb must agree with its grammatical subject — not the nearest noun, not the noun after a prepositional phrase, and not the complement. When in doubt, strip the sentence to Subject + Verb and check agreement there.

1.1 Intervening Phrases — The Most Common CDS Trap SPOTTING ERRORS

When a phrase comes between the subject and the verb, many students make the verb agree with the nearest noun instead of the actual subject. CDS exploits this in almost every paper.

Rule — Verb agrees with subject, not the nearest noun

✓ The quality of the reports was poor. (subject = quality, singular)

✗ The quality of the reports were poor.

✓ One of the soldiers was injured. (subject = one, singular)

✗ One of the soldiers were injured.

✓ The team, along with its officers, was deployed. (“along with” does not change subject)

✗ The team, along with its officers, were deployed.

Phrases that do NOT change singular subject to plural: along with, together with, as well as, in addition to, accompanied by, no less than, nothing but, rather than. The verb still agrees with the original subject.

CDS PYQSubject–Verb Agreement — Intervening Phrase

Q1. Find the error: “(A) The Commanding Officer, / (B) along with his platoon commanders, / (C) were present at the briefing / (D) No error”

Answer: (C) The subject is “The Commanding Officer” — singular. “Along with his platoon commanders” is a parenthetical phrase that does not make the subject plural. Use “was present”. This is the single most repeated SVA pattern in CDS Spotting Errors.

Q2. Find the error: “(A) Each of the cadets / (B) in the three batches / (C) have submitted their application / (D) No error”

Answer: (C) The subject is “Each” — always singular. The phrase “of the cadets in the three batches” is a modifier. Use “has submitted his/her application”. Two errors in one: wrong verb (“have”) and wrong pronoun (“their” after singular “each”).

1.2 Collective Nouns FILL IN THE BLANK

Collective noun acting as one unit → singular verb

The army was deployed on the border.
The committee has reached a decision.
The jury was unanimous in its verdict.
A number of soldiers were injured. (▲ “a number of” = plural)

Collective noun — members acting individually → plural verb

The team are arguing among themselves.
The jury are divided in their opinions.
Note: “the number of” = singular; “a number of” = plural
The number of recruits is increasing.

1.3 Either…or / Neither…nor — Proximity Rule SPOTTING ERRORS

Rule — Verb agrees with the subject nearest to it

✓ Either the CO or the soldiers were at fault. (soldiers = nearer = plural)

✓ Either the soldiers or the CO was at fault. (CO = nearer = singular)

✓ Neither he nor his colleagues were informed. (colleagues = nearer = plural)

1.4 Other High-Frequency SVA Rules

Subject Type	Verb	Example
Two singular subjects joined by and	Plural	The captain and the sergeant were* present.*
Each / every + noun + and + noun	Singular	Every officer and every soldier was* briefed.*
Subjects joined by as well as, with, together with	Agrees with 1st subject	The General, as well as his aides, was* present.*
News, mathematics, physics, politics, athletics	Always singular	The news is good. Mathematics is difficult.
A lot of / plenty of / most of	Depends on noun after it	A lot of soldiers were* present. A lot of water was spilled.*
None of	Singular (formal/CDS)	None of the soldiers was* injured.*
Fractions and percentages	Depends on noun after “of”	Half of the soldiers were* ready. Half of the water was gone.*
Titles of books, films, countries (plural form but single entity)	Singular	“The Three Musketeers” is a classic. The United States has* its policy.*

CDS PYQSubject–Verb Agreement — Mixed Patterns

Q3. Find the error: “(A) Neither the soldiers / (B) nor the officer / (C) were ready for inspection / (D) No error”

Answer: (C) With “neither…nor”, the verb agrees with the nearer subject. Here “officer” is nearest — singular — so use “was ready”. This proximity rule is tested every year. If the order were reversed (“neither the officer nor the soldiers”), “were” would be correct.

Q4. (CDS 2024-II pattern) Fill in the blank: “The number of applications received ___ far more than expected.”

(a) were
(b) was
(c) have been
(d) are

Answer: (b) was
“The number of” = singular (it refers to the number itself). “A number of” = plural (it means “several”). This contrast appears frequently in CDS Fill in the Blanks.

2. Tense Usage — CDS-Tested Patterns Only

CDS does not test tense formation. It tests tense errors — using the wrong tense in a given context. The four patterns below account for nearly all tense errors in CDS Spotting Errors and Sentence Improvement.

2.1 Simple Past vs Present Perfect SPOTTING ERRORS

Use Simple Past — when time is specified

With: yesterday, last week, in 1947, ago, then, when
✓ He joined the army in 2018.
✓ She passed the exam last year.
✗ He has joined the army in 2018.

Use Present Perfect — when time is unspecified / result matters

With: just, already, yet, ever, never, recently, so far, since, for
✓ He has just returned from the mission.
✓ She has never seen such courage.
✗ He just returned from the mission. (wrong with “just” in formal CDS context)

⚠ Classic CDS Tense Trap — “since” and “for”:
“Since” marks a point in time → use present perfect: He has served since 2015.
“For” marks a duration → use present perfect: He has served for ten years.
✗ He served since 2015. (simple past with “since” = error in CDS)

2.2 Past Perfect — When It Is Required SENTENCE IMPROVEMENT

Rule — Past perfect marks the earlier of two past events

✓ By the time the reinforcements arrived, the soldiers had already secured the perimeter.

✗ By the time the reinforcements arrived, the soldiers already secured the perimeter.

✓ He had completed his training before he was commissioned.

Trigger words that signal past perfect: before, after, by the time, when (both events in past), hardly…when, no sooner…than, as soon as (for the earlier event).

2.3 Sequence of Tenses — Reported Speech & Conditionals FILL IN THE BLANK

Context	Rule	Example
Reported speech (past reporting verb)	Direct present → past; direct past → past perfect	He said he was* tired. (not “is”)*
Universal / scientific truth (reported)	Stays in present tense even after past verb	She said the sun rises* in the east.*
Type 1 Conditional (real)	If + present simple, will + base	If he trains* hard, he will succeed.*
Type 2 Conditional (unreal present)	If + past simple, would + base	If he trained* harder, he would succeed.*
Type 3 Conditional (unreal past)	If + past perfect, would have + past participle	If he had trained, he would have succeeded.

CDS PYQTense Errors — CDS Pattern

Q5. Find the error: “(A) The officer said / (B) that he has completed / (C) the assignment the previous day / (D) No error”

Answer: (B) “The previous day” specifies a completed past time. After a past reporting verb (“said”), the tense shifts back: present perfect → past perfect. Correct: that he had completed the assignment the previous day.

Q6. (CDS 2024-I style) Sentence Improvement: “Hardly had the patrol left the camp when the enemy opened fire.”

(a) Hardly the patrol had left
(b) Hardly had the patrol left
(c) The patrol had hardly left
(d) No improvement needed

Answer: (d) No improvement needed
“Hardly…when” is a correct inversion structure. When “hardly”, “scarcely”, or “no sooner” begin a sentence, subject-auxiliary inversion applies: Hardly had [subject] [past participle]… The sentence is grammatically correct as written. This tests whether students know when not to change a sentence.

Q7. Fill in the blank: “If the CO ___ the correct map, the platoon would not have lost its way.”

(a) had
(b) has had
(c) had had
(d) would have had

Answer: (c) had had
This is a Type 3 conditional (unreal past situation): If + past perfect in the if-clause, would have + past participle in the main clause. “Had had” = past perfect of “have”. The structure confirms the event did NOT happen in the past. Option (d) is wrong — “would have had” cannot appear in the if-clause.

3. Infinitive vs Gerund — Verb + Verb Patterns

CDS tests this specifically: Certain verbs are always followed by a gerund (-ing), others always by a to-infinitive, and a small group can take both (with a change in meaning). Getting this wrong is a classic Sentence Improvement error.

3.1 Verbs Always Followed by Gerund (-ing) SENTENCE IMPROVEMENT

Gerund-only verbs (most tested in CDS)

enjoy, avoid, mind, suggest, recommend
consider, keep, practise, finish, stop (= quit)
deny, admit, risk, resist, postpone, delay
can’t help, can’t stand, look forward to
✓ He avoided making eye contact.
✗ He avoided to make eye contact.

Infinitive-only verbs (most tested in CDS)

want, wish, hope, expect, decide, plan
agree, refuse, fail, manage, tend, seem
offer, promise, threaten, dare, afford
learn, pretend, hesitate, deserve, claim
✓ He decided to join the NDA.
✗ He decided joining the NDA.

3.2 Verbs That Change Meaning with Gerund vs Infinitive TRICKY

Verb	Form	Meaning	Example
stop	+ gerund	Quit doing something	He stopped smoking. (he quit)
stop	+ infinitive	Pause in order to do something else	He stopped to smoke. (he paused to smoke)
remember	+ gerund	Recall a past action	I remember locking* the door.* (I recall doing it)
remember	+ infinitive	Remember to do something (future task)	Remember to lock* the door.* (don’t forget)
forget	+ gerund	Forget a past action	I’ll never forget meeting* the General.*
forget	+ infinitive	Forget to do a future task	Don’t forget to submit* your form.*
try	+ gerund	Experiment with something	Try drinking more water. (as an experiment)
try	+ infinitive	Attempt (with difficulty)	He tried to lift* the weight.* (attempt)
regret	+ gerund	Regret a past action	I regret saying* that.*
regret	+ infinitive	Regret to inform (formal announcement)	I regret to inform* you of this.*

CDS PYQInfinitive vs Gerund

Q8. Find the error: “(A) He suggested / (B) to postpone / (C) the exercise / (D) No error”

Answer: (B) “Suggest” is always followed by a gerund, not an infinitive. Correct: He suggested postponing the exercise.
Alternative correct forms: “He suggested that we postpone” (subjunctive) or “He suggested postponing”. Never “suggest to do”.

Q9. (CDS 2025-I style) Sentence Improvement: “He stopped to smoke after the doctor’s warning.”

(a) He stopped smoking after the doctor’s warning.
(b) He stopped to have smoked after the doctor’s warning.
(c) He had stopped to smoke after the doctor’s warning.
(d) No improvement needed

Answer: (a) “Stopped to smoke” means he paused (in order) to smoke — the opposite of what the doctor warned about. The intended meaning is that he quit smoking → use “stopped smoking” (gerund = quitting). This stop + gerund vs stop + infinitive distinction is a confirmed CDS Sentence Improvement pattern.

4. Confusable Verb Pairs — Rise/Raise, Lie/Lay, Sit/Set

Why this matters for CDS: These three pairs are consistently tested in Spotting Errors because they are confused in everyday speech. The key distinction is transitive vs intransitive — whether the verb needs an object or not.

Verb	Meaning	Takes Object?	Present	Past	Example
rise	Go up (by itself)	No (intransitive)	rise / rises	rose / risen	The sun rises* in the east.*
raise	Lift something up	Yes (transitive)	raise / raises	raised	He raised* his hand.*
lie	Recline / be situated	No (intransitive)	lie / lies	lay / lain	He lay* on the ground. (past of lie)*
lay	Put something down	Yes (transitive)	lay / lays	laid	She laid* the map on the table.*
sit	Take a seat (by itself)	No (intransitive)	sit / sits	sat	The officer sat* down.*
set	Place something	Yes (transitive)	set / sets	set	She set* the files on the desk.*

⚠ The Biggest Confusion — “lay” as past of “lie”:
“Lay” has two identities: (1) present tense of “lay” (to place something), and (2) past tense of “lie” (to recline).
✓ Yesterday, the wounded soldier lay on the stretcher. (past of lie — no object)
✓ The medic laid the soldier on the stretcher. (past of lay — object: “the soldier”)
✗ The soldier lied on the stretcher. (wrong — “lied” means told a lie)

TRICKY QRise / Raise / Lie / Lay — CDS Error Pattern

Q. Identify the errors: “The prices of essential goods have raised sharply, and the soldiers were asked to lay on the ground during the drill.”

Error 1: “have raised” → “Raise” is transitive (needs an object). Prices go up by themselves → use intransitive “have risen”.
Error 2: “lay” → Since this is passive voice (“were asked to ___”), the verb after “to” must be the base form. “Lay” here is being used to mean “recline”, but the infinitive of “lie” (recline) is just “lie”. Correct: “to lie on the ground”.
Corrected: The prices of essential goods have risen sharply, and the soldiers were asked to lie on the ground during the drill.

5. Active and Passive Voice — Spotting the Error

CDS does not ask you to convert active to passive in isolation. It tests: (1) whether the passive is formed correctly (wrong auxiliary / wrong participle), and (2) whether active or passive is appropriate in a given context. Intransitive verbs cannot be made passive.

Common Passive Formation Errors

✗ The letter was wrote by him. → written (past participle, not past tense)
✗ The work is been completed. → has been completed
✗ He was saw by the officer. → was seen
✓ The order was given by the CO.

Intransitive verbs — cannot be made passive

✗ The accident was happened. (happen = intransitive)
✗ The train was arrived. (arrive = intransitive)
✗ He was died. (die = intransitive)
Rule: Only transitive verbs (those with objects) can form passive voice.

6. Subjunctive Mood — wish, if I were, it is time

The subjunctive is a small but consistently tested area in CDS. It uses past tense forms to express present/future unreal situations, or “were” for all persons when expressing a wish or hypothetical.

Three subjunctive structures tested in CDS

✓ I wish I were a pilot. (not “was” — subjunctive uses “were” for all persons)

✓ If I were the CO, I would change this rule. (hypothetical, not “was”)

✓ It is time we left. / It is time he went to bed. (past tense after “it is time”)

✗ I wish I was a pilot. ✗ If I was the CO… ✗ It is time we leave.

CDS PYQSubjunctive Mood

Q10. Find the error: “(A) If I was / (B) in his position, / (C) I would have resigned / (D) No error”

Answer: (A) This is a hypothetical / unreal present situation (I am NOT in his position). The subjunctive requires “were” for all persons in such constructions, not “was”. Correct: If I were in his position, I would have resigned.

Q11. (CDS 2023-II style) Find the error: “(A) It is high time / (B) the government / (C) takes action on this matter / (D) No error”

Answer: (C) After “It is (high) time”, the verb in the subordinate clause must be in simple past tense, not present. Correct: It is high time the government took action on this matter. This pattern is tested in nearly every CDS paper.

PART B — HELPING VERBS (MODALS)

7. Modal Verbs — Meaning and CDS-Tested Errors

CDS tests modals in two ways: (1) choosing the correct modal for a given meaning (Fill in the Blank), and (2) spotting wrong modal usage in a sentence (Spotting Errors). The key is knowing the precise meaning difference between close pairs like can/could, may/might, shall/will, must/ought to, should/would.

Modal	Primary Meaning in CDS Context	Correct Example	Common Error
can	Present ability; informal permission	He can* run 10 km.*	He can to run. (no “to” after modals)
could	Past ability; polite request; conditional ability	He could* lift that when young. / Could you help?*	could + have + past participle for unreal past
may	Formal permission; present possibility	You may* leave now. / It may rain.*	Using “can” for formal permission
might	Weaker/remote possibility; past of “may” in reported speech	He might* arrive late.*	might + have + pp for unreal past criticism
shall	Future with I/we (intention); determination with you/he	I shall* return. / You shall not pass.*	shall with he/she/they for simple future
will	Future (all persons in modern usage); willingness; promise	He will* report at 0600.*	Using “will” in if-clause: if he will come
should	Obligation / advice; expectation; after “lest”	You should* report on time. / Lest he should fail.*	should in if-clause (Type 2 conditional)
would	Past habit; conditional; polite request	He would* go for a run every morning.*	would in if-clause of Type 2/3 conditional
must	Strong obligation / necessity; logical certainty	You must* submit by Friday. / He must be tired.*	mustn’t vs needn’t distinction
ought to	Moral obligation / advisability (= should, but stronger)	You ought to* respect your superiors.*	ought to + bare infinitive (no “to” is wrong here)
need not	No obligation (absence of necessity)	You needn’t* report tomorrow. (holiday)*	Confusing with mustn’t (prohibition)
dare	Challenge / courage; used as modal in negatives & questions	How dare* he disobey orders? / He dare not speak.*	How dare he to disobey.

7.1 must not vs need not — A Classic CDS Distinction FILL IN THE BLANK

mustn’t = Prohibition (you are not allowed to)

✓ You mustn’t carry your phone into the exam. (it is forbidden)
✓ Soldiers must not reveal operational details.
Strong negative obligation — something is prohibited

needn’t = No obligation (you are not required to)

✓ You needn’t report tomorrow — it’s a holiday. (not required)
✓ She needn’t bring her own equipment.
Absence of obligation — something is unnecessary

CDS PYQModal Verbs — Fill in the Blank & Spotting Errors

Q12. Fill in the blank: “You ___ carry ID proof — it is compulsory for entry.”

(a) should
(b) must
(c) might
(d) could

Answer: (b) must
“Compulsory” signals strong obligation with no alternative → must. “Should” implies advice (you ought to but may not). “Might/could” imply possibility, not obligation. “Must” = strong duty or necessity.

Q13. Find the error: “(A) The new recruits / (B) need not to report / (C) before 0800 hours / (D) No error”

Answer: (B) When “need” is used as a modal auxiliary, it takes the bare infinitive (no “to”). Correct: need not report (not “need not to report”). If “need” is a main verb, then “to” is used: “They do not need to report” — but “need not + bare infinitive” is the standard modal form tested in CDS.

Q14. (CDS 2025-II style) Fill in the blank: “Lest you ___ fail, revise all the topics before the examination.”

(a) will
(b) would
(c) should
(d) shall

Answer: (c) should
After “lest”, the subordinate clause must use “should” (not will, would, or shall). This is a fixed grammatical rule: Lest + subject + should + bare infinitive. “Lest you should fail” = so that you do not fail. This appears in CDS Fill in the Blanks regularly.

8. Perfect Modal Constructions — Unreal Past

Modal + have + past participle is used to talk about unreal, hypothetical, or regretted situations in the past. CDS tests whether students can identify the correct modal for a given meaning in this structure.

Structure	Meaning	Example
should have + pp	Past obligation not fulfilled (criticism / regret)	You should have informed* me earlier. (but you didn’t)*
could have + pp	Past ability that was not used (missed opportunity)	He could have won* if he had tried harder.*
would have + pp	Unreal result (Type 3 conditional main clause)	She would have passed* if she had studied.*
must have + pp	Logical certainty about a past event	He must have left* already — his bag is gone.*
may/might have + pp	Possibility that something happened in the past	He might have forgotten* about the briefing.*
need not have + pp	Did something unnecessarily (it wasn’t required)	You need not have rushed* — the train is late.*

CDS PYQPerfect Modals — Spotting Errors & Sentence Improvement

Q15. Find the error: “(A) He must have / (B) informed the CO / (C) before he left the camp / (D) No error”

Answer: (A) or (D) — context-dependent.
If the intended meaning is logical certainty (he certainly informed the CO), then “must have informed” is correct → No error.
If the intended meaning is obligation not fulfilled (he didn’t inform but should have), then it should be “should have informed”. This type of question in CDS requires reading the intended meaning carefully before selecting the error.

Q16. (CDS 2024-I style) Sentence Improvement: “You need not have to submit the form again.”

(a) You need not submit the form again.
(b) You did not need to have submitted the form again.
(c) You need not have submitted the form again.
(d) No improvement needed

Answer: (c) “Need not have + past participle” = you did it, but it was unnecessary. The original “need not have to submit” mixes modal forms incorrectly. Option (a) “need not submit” would imply a present obligation — different meaning. Option (c) correctly expresses that the submission was unnecessary and already done.

9. used to / be used to / get used to — A Confirmed CDS Trap

These three are visually similar but grammatically completely different. CDS has tested this distinction in both Fill in the Blank and Sentence Improvement. Getting the form wrong is a very common error.

“used to” + bare infinitive

Past habit or state that no longer exists
✓ He used to run every morning. (past habit, now stopped)
✓ There used to be a fort here.
✗ He used to running.

“be used to” + gerund (-ing)

Accustomed to something (present or past state)
✓ He is used to working long hours. (accustomed)
✓ She was used to living in the hills.
✗ He is used to work long hours.

“get used to” + gerund (-ing)

Become accustomed (process of adapting)
✓ He will get used to waking up early.
✓ She got used to living alone.
✗ He got used to wake up early.

CDS PYQused to / be used to / get used to

Q17. Find the error: “(A) The cadet / (B) is used to / (C) wake up at 0500 hours / (D) No error”

Answer: (C) “Be used to” must be followed by a gerund (-ing form), not a bare infinitive. Correct: The cadet is used to waking up at 0500 hours.
Contrast: “The cadet used to wake up at 0500” (past habit, now changed) — here “used to” takes the bare infinitive.

Q18. Fill in the blank: “When he joined the field unit, he had to ___ living without modern conveniences.”

(a) used to
(b) be used to
(c) get used to
(d) use to

Answer: (c) get used to
The sentence describes a process of becoming accustomed (he had to adapt) → “get used to” + gerund. “Used to” (a) would require a bare infinitive and means a past habit. “Be used to” (b) describes being already accustomed, not the process of becoming so. “Use to” (d) is not standard.

TRICKY QModal + Tense Combined Errors — CDS Pattern

Q. Identify the error: “If he would have prepared better, he could have cleared the CDS exam.”

Error: “would have prepared” in the if-clause → Wrong. In a Type 3 conditional (unreal past), the if-clause must use past perfect (had + past participle), never “would have”. “Would have” belongs only in the result clause.
Correct: If he had prepared better, he could have cleared the CDS exam.
Rule to remember: “Would” never appears in the if-clause of any conditional — Type 1, 2, or 3.

Q. Find all errors: “He dare not to speak, nor he can afford to lose this opportunity.”

Error 1: “dare not to speak” → When “dare” is used as a modal, it takes the bare infinitive. Write: He dare not speak.
Error 2: “nor he can” → After “nor” at the start of a clause, inversion is required (auxiliary before subject). Write: nor can he afford…
Corrected: He dare not speak, nor can he afford to lose this opportunity.

10. do / does / did — Common Error in Questions and Negatives

Rule — do/does/did take bare infinitive; main verb does not inflect

✓ He does not report on time. (not “does not reports”)

✗ He does not reports on time. (double inflection error)

✓ Did she submit the form? (not “did she submitted”)

✗ Did she submitted the form? (past tense already in “did”)

✓ He did complete the task. (emphatic do — adds stress, use bare infinitive)

📋 Quick Reference — Verbs & Helping Verbs

▲ SVA — Intervening Phrases

“along with / together with / as well as” → do not change subject number
Verb agrees with first (real) subject
“a number of” → plural verb
“the number of” → singular verb

⏳ Tense Triggers

yesterday / ago / in [year] → simple past
just / already / since / for / yet / ever → present perfect
before / by the time / hardly…when → past perfect (earlier event)
if + past simple + would → Type 2 conditional

📄 Gerund vs Infinitive

enjoy, avoid, suggest, admit, risk, deny → gerund only
want, wish, decide, agree, refuse, manage → infinitive only
stop, remember, forget, try, regret → both (meaning changes)
“suggest to do” → WRONG (suggest + gerund)

🚫 Subjunctive Rules

“I wish I were” (not was)
“If I were in his place” (not was)
“It is time he went” (past tense, not “goes”)
“Lest he should fail” (always “should”)

🚫 Modals — Key Rules

No “to” after modals (except ought to)
“would” never in the if-clause
mustn’t = prohibited; needn’t = not required
Lest + should + bare infinitive

🔄 Perfect Modals

should have + pp → obligation not fulfilled
could have + pp → missed opportunity
must have + pp → logical certainty (past)
need not have + pp → done unnecessarily

🔄 used to / be used to

used to + bare infinitive → past habit (no longer)
be used to + gerund → accustomed to
get used to + gerund → process of adapting
“is used to work” → WRONG (working)

⚠ Rise vs Raise / Lie vs Lay

rise (intransitive) → rose → risen
raise (transitive, needs object) → raised
lie (intransitive) → lay → lain
lay (transitive) → laid; “lay” = past of lie

⚠ Top CDS Verb Traps

“along with” doesn’t make subject plural
“if I was” → WRONG (were — subjunctive)
“does not reports” → WRONG (does not report)
“would have prepared” in if-clause → WRONG
“need not to report” → WRONG (need not report)

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