Chapter 13
Modals
Theory
3.1 Master Table of Modals
| Modal | Principal Meaning(s) | Example |
|---|---|---|
| can | ability; informal permission; possibility | She can speak French. |
| could | past ability; polite request; possibility | Could you help me, please? |
| may | formal permission; possibility; wish/blessing | May you live long! |
| might | remote/faint possibility; very polite | It might rain later. |
| shall | 1st-person future; offers/suggestions; legal obligation | Shall I open the window? |
| should | advice; obligation; expectation; past unfulfilled (should have) | You should see a doctor. |
| will | future; willingness; characteristic habit | I will help you. |
| would | past habit; polite request; conditionals; would rather | We would play here as children. |
| must | strong obligation/necessity; logical certainty | You must stop at a red light. |
| ought to | moral obligation; advice; expectation | You ought to respect your elders. |
| need | necessity (chiefly in negatives/questions) | You needn't worry. |
| dare | to have the courage to | How dare you say that? |
| used to | past habit/state no longer true | I used to live in Lucknow. |
| had better | strong advice/warning (present-future) | You had better leave now. |
| would rather | preference | I would rather walk than wait. |
Golden rule: A modal + bare infinitive (no "to") — except ought to, used to, have to, need to. Never use two modals together; never add -s; never add "to" after can/may/must, etc.
3.2 CAN — ability, informal permission, possibility
- A parrot can imitate human speech. (ability)
- You can take my pen. (informal permission)
- Anyone can make a mistake. (general possibility)
- Can you lift this box? (ability — question)
- The roads can be very slippery in winter. (possibility)
3.3 COULD — past ability, polite request, possibility
- At five she could already read. (past ability)
- Could you pass the salt, please? (polite request)
- This news could be true. (present possibility)
- We could go to the cinema tonight. (suggestion)
- I could swim across the river when I was young. (past general ability)
For a single successful action in the past use was/were able to or managed to, not could: "He was able to escape the fire" (not "could escape" in the affirmative single-event sense). In negatives, couldn't is fine: "He couldn't escape."
3.4 MAY — formal permission, possibility, wish/blessing
- May I come in, sir? (formal permission)
- He may arrive by the evening train. (possibility)
- May God bless you! (wish/blessing)
- You may leave when you have finished. (permission)
- It may snow on the hills tonight. (possibility)
3.5 MIGHT — remote possibility, very polite
- We might win the match, but I doubt it. (remote possibility)
- Might I borrow your umbrella? (very polite/formal request)
- If you hurried, you might catch the bus. (conditional possibility)
- She might not have heard the bell. (uncertain past — with perfect)
- He said he might come. (reported — past of "may")
3.6 SHALL — 1st-person future, offers/suggestions, legal obligation
- I shall be twenty next month. (1st-person future)
- Shall I carry your bag? (offer)
- Shall we dance? (suggestion)
- The tenant shall pay the rent monthly. (legal/formal obligation)
- We shall overcome these difficulties. (determination/future)
3.7 SHOULD — advice, obligation, expectation, past unfulfilled
- You should brush your teeth twice a day. (advice)
- Students should respect their teachers. (obligation/duty)
- The train should arrive at six. (expectation)
- You should have told me earlier. (past unfulfilled duty — you didn't)
- He should be in his office now. (logical expectation)
3.8 WILL — future, willingness, habit
- They will reach Delhi tomorrow. (future)
- I will carry this for you. (willingness/promise)
- Oil will float on water. (characteristic/general truth)
- She will sit for hours staring at the sea. (typical habit)
- Will you please be quiet? (request)
3.9 WOULD — past habit, polite request, conditionals, would rather
- Every summer we would visit our grandparents. (past habit)
- Would you mind opening the door? (polite request)
- If I had money, I would buy a car. (conditional)
- I would rather stay at home tonight. (preference)
- He promised that he would come. (future-in-the-past)
would rather + bare infinitive: "I would rather go now." With a different subject use the past tense: "I would rather you went now."
3.10 MUST — obligation, strong necessity, logical certainty
- You must obey the rules. (obligation, speaker's authority)
- I must finish this work today. (felt necessity)
- You must be tired after the journey. (logical certainty/deduction)
- We must not waste water. (= mustn't — prohibition)
- She has worked all day; she must be hungry. (deduction)
3.11 MUSTN'T vs NEEDN'T
Mustn't = prohibition (it is forbidden / don't do it). Needn't = absence of necessity (it is not required, but you may if you wish).
- You mustn't smoke here. (it is forbidden)
- You needn't come early; the meeting starts late. (not necessary)
- Visitors mustn't feed the animals. (prohibition)
- You needn't pay now; pay next week. (no necessity)
- Children mustn't play with fire. (forbidden)
3.12 OUGHT TO — moral obligation, advice, expectation
- We ought to help the poor. (moral duty)
- You ought to apologise to her. (advice)
- He ought to be here by now. (expectation)
- You ought not to tell lies. (moral advice — negative)
- They ought to have warned us. (past unfulfilled duty)
3.13 NEED — necessity (needn't have vs didn't need to)
As a modal, need is used chiefly in negatives and questions and takes a bare infinitive: "You needn't go." As an ordinary verb it takes "to": "You don't need to go."
- Need I repeat the instructions? (modal question)
- You needn't wait for me. (no present necessity)
- You needn't have bought milk — we already had some. (you bought it, but it was unnecessary)
- I didn't need to buy milk, so I didn't. (it wasn't necessary; action not done)
- She needn't have hurried; the train was late. (she hurried unnecessarily)
3.14 DARE
- How dare you speak to me like that! (modal — bare infinitive)
- He dare not contradict the boss. (modal negative)
- She doesn't dare to jump. (ordinary verb with "to")
- Dare he face the truth? (modal question)
- I daren't tell him the news. (modal negative)
3.15 USED TO — past habit/state
- I used to smoke, but I gave it up. (past habit, now stopped)
- There used to be a temple here. (past state)
- We used to walk to school. (past repeated action)
- He didn't use to like tea. (negative)
- Did you use to play cricket? (question)
Do not confuse used to + V1 (past habit) with be/get used to + V-ing (be accustomed): "I am used to working late."
3.16 HAD BETTER / HAD BETTER NOT — strong advice/warning
- You had better see a doctor. (strong advice)
- We had better hurry or we'll miss the flight. (warning)
- You had better not be late again. (warning — negative)
- He'd better apologise. (contracted)
- You had better not touch that wire. (caution)
had better is followed by a bare infinitive and refers to the present/future, never the past, despite the form "had".
3.17 Perfect Modals (modal + have + V3)
Perfect modals comment on the past. Learn each meaning precisely:
| Form | Meaning | Example |
|---|---|---|
| must have + V3 | logical certainty about the past (it certainly happened) | The ground is wet; it must have rained. |
| can't have / couldn't have + V3 | logical impossibility about the past (it certainly did not happen) | She can't have finished so soon. |
| may have / might have + V3 | uncertain possibility about the past (perhaps) | He may have missed the bus. |
| could have + V3 | past unrealised ability/possibility; reproach | You could have warned me! |
| should have / ought to have + V3 | past duty not done (it didn't happen) | You should have studied harder. |
| would have + V3 | unreal past result (3rd conditional) | I would have come if you had called. |
| needn't have + V3 | did it, but it was unnecessary | You needn't have cooked — we ate out. |
- The lights are off; they must have gone out. (certainty)
- He can't have stolen it — he was with me all day. (impossibility)
- They might have forgotten the appointment. (possibility)
- You should have informed the police at once. (unfulfilled duty)
- We needn't have rushed; the show started late. (unnecessary action that was done)
Common Exam Errors
| # | Wrong | Correct | Explanation |
|---|---|---|---|
| 1 | He can to drive a car. | He can drive a car. | A modal takes a bare infinitive (no "to"). |
| 2 | She musts go now. | She must go now. | Modals never take "-s" in the third person singular. |
| 3 | He will can help you. | He will be able to help you. | Two modals cannot be used together. |
| 4 | You mustn't worry; it is not compulsory. | You needn't worry; it is not compulsory. | "Mustn't" = prohibition; "needn't" = no necessity. |
| 5 | I used to playing chess as a boy. | I used to play chess as a boy. | "Used to" is followed by the bare infinitive. |
| 6 | He could escape from the burning house. | He was able to escape from the burning house. | Single successful past act uses "was able to", not "could". |
| 7 | You had better to rest. | You had better rest. | "Had better" takes a bare infinitive. |
| 8 | I would rather to walk. | I would rather walk. | "Would rather" takes a bare infinitive. |
| 9 | May you live long? (as a wish) | May you live long! | A blessing/wish with "may" is an exclamation, not a question. |
| 10 | You needn't have not come. | You needn't have come. | "Needn't have + V3" already conveys the unnecessary action. |
| 11 | He don't dare to oppose. | He dare not oppose. / He doesn't dare to oppose. | As a modal "dare not"; as an ordinary verb "doesn't dare to". |
| 12 | We must to obey the law. | We must obey the law. | "Must" takes a bare infinitive. |
| 13 | I am used to walk daily. | I am used to walking daily. | "Be used to" (accustomed) takes a gerund. |
| 14 | Shall he go now? (ordinary future) | Will he go now? | For 2nd/3rd-person plain future, "will" is standard. |
| 15 | You should have to apologise. | You should apologise. | Do not combine "should" with "have to" here. |
| 16 | It must rained last night. | It must have rained last night. | Past deduction needs "must have + V3". |
| 17 | He can't have went there. | He can't have gone there. | After "have" use the past participle (V3). |
| 18 | Can I borrow your pen? — said very formally to a stranger. | May I borrow your pen? | "May" is the formal/polite permission form. |
| 19 | Would you mind to open the window? | Would you mind opening the window? | "Mind" is followed by a gerund. |
| 20 | I didn't needn't to pay. | I didn't need to pay. | "Didn't need to" expresses absence of past necessity. |
| 21 | You ought respect your parents. | You ought to respect your parents. | "Ought" is always followed by "to". |
| 22 | There use to be a well here. | There used to be a well here. | In the affirmative the form is "used to". |
| 23 | If I were rich, I will travel the world. | If I were rich, I would travel the world. | The result clause of an unreal conditional needs "would". |
| 24 | You had not better go there. | You had better not go there. | The negative of "had better" is "had better not". |
| 25 | She might comes tomorrow. | She might come tomorrow. | Modals take a bare infinitive without "-s". |
Exam Tricks
- "Wet ground / clue in the past" + certainty → choose must have; if it is impossible, choose can't have / couldn't have.
- Reproach about the past ("Why didn't you…?") → should have / could have / ought to have.
- "It was done but pointlessly" → needn't have done; "it wasn't necessary" → didn't need to.
- Prohibition signal ("forbidden / not allowed") → mustn't; "not necessary / optional" → needn't.
- Polite request to a stranger / superior → could / would / may / might, not "can".
- Past repeated habit → used to / would; but a past state → only used to (not "would": "I used to own a bike," not "would own").
- 3rd conditional result clause → would/could/might have + V3.
- Distractor traps: "can to", "will can", "musts", "ought respect", "used to playing" (for past habit), "had better to", "mustn't" where "needn't" is meant.
- Watch for the "to"-trap: only ought to, used to, have to, need to keep "to"; all other modals drop it.
Frequently Confused Pairs
| Pair | Distinction | Example |
|---|---|---|
| must / have to | "must" = speaker's own authority or strong inner necessity; "have to" = external obligation/rule. | I must stop smoking (my decision) vs. I have to wear a uniform (rule). |
| mustn't / needn't | "mustn't" = prohibition; "needn't" = no necessity. | You mustn't park here vs. You needn't wait. |
| can / may | "can" = informal permission/ability; "may" = formal permission. | Can I sit here? (informal) vs. May I sit here? (formal). |
| should / must | "should" = advice/desirable; "must" = compulsion/strong obligation. | You should exercise (advice) vs. You must pay tax (compulsory). |
| used to / would | Both = past habit; only "used to" expresses a past state. | I used to have long hair (state — not "would") vs. We would/used to swim daily (action). |
| needn't have / didn't need to | "needn't have + V3" = the action was done but unnecessary; "didn't need to" = it was not necessary (often not done). | You needn't have waited (you did) vs. I didn't need to wait (so I left). |
| will / would | "will" = present willingness/future; "would" = polite, conditional, or past habit. | I will help vs. Would you help me? |
Exceptions — Important, Rare & Advanced
- "Could" for a single past achievement is wrong in the affirmative; use was/were able to. But in the negative ("couldn't") and with verbs of perception ("could see/hear/feel") it is acceptable: "I could see the stars."
- "Shall" in legal English expresses obligation for all persons: "The contractor shall complete the work by June."
- "May" / "might" in concessive clauses: "Try as he may, he cannot win."
- "Will" for insistence/annoyance: "He will keep interrupting!" (stressed).
- "Dare" and "need" behave as modals in negatives/questions but as ordinary verbs elsewhere — a "mixed" verb pattern.
- "Had better" looks past but is present/future in meaning; its negative is had better not, not "had not better".
- "Would rather … than" compares two actions: "I would rather read than watch TV." With a clause it takes the past subjunctive: "I would rather you didn't smoke."
- Double obligation removed: the past of "must" (obligation) is "had to"; "must" has no past form of its own except in deduction ("must have").
- "May" vs "might" in reported speech: "may" becomes "might" — "He said he might be late."
- "Cannot but / can but": "I cannot but admire her courage" (= I can only admire).
50 MCQs
Easy (1–15)
1. Choose the correct sentence.
(a) He can to swim. (b) He can swim. (c) He can swims. (d) He cans swim.
Answer: (b) He can swim.
Explanation: A modal takes a bare infinitive without "to" and without "-s".
2. ___ I come in, sir?
(a) Will (b) Shall (c) May (d) Would
Answer: (c) May
Explanation: "May" expresses formal/polite permission.
3. You ___ stop when the traffic light is red.
(a) must (b) may (c) might (d) could
Answer: (a) must
Explanation: "Must" expresses strong obligation/rule.
4. We ___ visit the zoo every Sunday when we were children.
(a) would (b) will (c) shall (d) can
Answer: (a) would
Explanation: "Would" expresses a repeated past habit.
5. ___ you please pass me the salt?
(a) Shall (b) Could (c) Must (d) May
Answer: (b) Could
Explanation: "Could" makes a polite request.
6. There ___ be a cinema here, but it closed long ago.
(a) would (b) used to (c) will (d) shall
Answer: (b) used to
Explanation: A past state uses "used to", not "would".
7. You ___ smoke in the hospital; it is forbidden.
(a) needn't (b) mustn't (c) shouldn't (d) wouldn't
Answer: (b) mustn't
Explanation: "Mustn't" expresses prohibition.
8. You ___ worry; the work is already done.
(a) mustn't (b) couldn't (c) needn't (d) daren't
Answer: (c) needn't
Explanation: "Needn't" expresses absence of necessity.
9. ___ I carry your luggage for you?
(a) Shall (b) Will (c) Would (d) Should
Answer: (a) Shall
Explanation: "Shall I?" makes an offer.
10. You ___ respect your elders.
(a) ought (b) ought to (c) must to (d) should to
Answer: (b) ought to
Explanation: "Ought" is always followed by "to".
11. She ___ speak three languages fluently.
(a) may (b) can (c) shall (d) ought
Answer: (b) can
Explanation: "Can" expresses ability.
12. It ___ rain this evening, so take an umbrella.
(a) shall (b) must (c) may (d) ought
Answer: (c) may
Explanation: "May" expresses possibility.
13. You ___ leave now, or you will miss the train.
(a) had better (b) had better to (c) better had (d) would rather
Answer: (a) had better
Explanation: "Had better" + bare infinitive gives strong advice.
14. I ___ rather have tea than coffee.
(a) would (b) should (c) will (d) ought
Answer: (a) would
Explanation: "Would rather" expresses preference.
15. ___ God bless you with good health!
(a) Can (b) May (c) Shall (d) Will
Answer: (b) May
Explanation: "May" expresses a wish/blessing.
Moderate (16–35)
16. The ground is wet; it ___ during the night.
(a) must rain (b) must have rained (c) must be raining (d) had to rain
Answer: (b) must have rained
Explanation: Past deduction uses "must have + V3".
17. He ___ the box yesterday; he was very weak.
(a) could lift (b) can lift (c) was not able to lift (d) must lift
Answer: (c) was not able to lift
Explanation: A single past (in)ability prefers "be able to"; here the negative fits the context.
18. You ___ told me earlier; now it is too late.
(a) should have (b) must have (c) needn't have (d) can have
Answer: (a) should have
Explanation: "Should have + V3" = past duty not fulfilled.
19. You ___ cooked so much; only two guests came.
(a) didn't need to (b) needn't have (c) mustn't have (d) shouldn't
Answer: (b) needn't have
Explanation: "Needn't have + V3" = you did it, but it was unnecessary.
20. As it was a holiday, I ___ go to office.
(a) needn't have (b) didn't need to (c) mustn't (d) couldn't have
Answer: (b) didn't need to
Explanation: "Didn't need to" = it was not necessary (and not done).
21. He ___ have stolen the watch; he was abroad at the time.
(a) must (b) should (c) can't (d) may
Answer: (c) can't
Explanation: "Can't have + V3" expresses past impossibility.
22. I ___ wear a uniform; it is a company rule.
(a) must (b) have to (c) should (d) ought to
Answer: (b) have to
Explanation: An external rule is best expressed by "have to".
23. If I had known, I ___ you.
(a) will help (b) would help (c) would have helped (d) had helped
Answer: (c) would have helped
Explanation: Third conditional result clause = "would have + V3".
24. She said she ___ attend the meeting.
(a) may (b) might (c) can (d) shall
Answer: (b) might
Explanation: In reported speech "may" becomes "might".
25. You ___ better not tell anyone about this.
(a) would (b) had (c) should (d) ought
Answer: (b) had
Explanation: The negative warning is "had better not".
26. I am used to ___ early in the morning.
(a) wake (b) woke (c) waking (d) wakes
Answer: (c) waking
Explanation: "Be used to" (accustomed) is followed by a gerund.
27. How ___ you speak to your teacher like that!
(a) dare (b) dares (c) daring (d) to dare
Answer: (a) dare
Explanation: Modal "dare" takes a bare infinitive and no "-s".
28. He ___ be in his office; the lights are on.
(a) must (b) can't (c) needn't (d) used to
Answer: (a) must
Explanation: "Must" expresses logical certainty/deduction.
29. ___ we go for a walk now?
(a) Shall (b) Must (c) Ought (d) Need
Answer: (a) Shall
Explanation: "Shall we?" makes a suggestion.
30. Try as he ___, he could not solve the puzzle.
(a) can (b) might (c) shall (d) will
Answer: (b) might
Explanation: "Try as he might" is the fixed concessive idiom.
31. You ___ have to repeat the year if you fail.
(a) will (b) shall (c) would (d) used to
Answer: (a) will
Explanation: Future obligation uses "will have to".
32. We ___ to obey the laws of the land.
(a) must (b) ought (c) should (d) can
Answer: (b) ought
Explanation: Only "ought" takes "to"; the others would not.
33. ___ you mind closing the window?
(a) Will (b) Would (c) Shall (d) May
Answer: (b) Would
Explanation: "Would you mind …?" is the polite-request pattern.
34. He ___ not contradict his father.
(a) dares (b) dare (c) daring (d) to dare
Answer: (b) dare
Explanation: In the negative, modal "dare not" takes the bare infinitive.
35. They ___ have reached home by now; it is very late.
(a) should (b) must (c) need (d) dare
Answer: (a) should
Explanation: "Should have + V3" here expresses reasonable expectation about the recent past.
Difficult (36–50)
36. "The tenant ___ vacate the premises within thirty days," reads the agreement.
(a) will (b) shall (c) would (d) can
Answer: (b) shall
Explanation: In legal English "shall" expresses obligation for all persons.
37. I ___ you didn't interrupt me while I am speaking.
(a) would rather (b) had better (c) used to (d) ought to
Answer: (a) would rather
Explanation: "Would rather + subject + past tense" expresses a preference about someone else's action.
38. She ran all the way, but she ___; the train was delayed.
(a) didn't need to hurry (b) needn't have hurried (c) mustn't hurry (d) couldn't hurry
Answer: (b) needn't have hurried
Explanation: She did hurry, but it proved unnecessary — "needn't have + V3".
39. He ___ have passed; he hardly studied at all, yet here is his result.
(a) can't (b) must (c) needn't (d) shouldn't
Answer: (b) must
Explanation: Given the result, certainty about the past = "must have".
40. Choose the grammatically correct sentence.
(a) He will can finish it. (b) He shall be able to finish it. (c) He must to finish it. (d) He can finishes it.
Answer: (b) He shall be able to finish it.
Explanation: Two modals cannot combine; "be able to" supplies the missing modal meaning.
41. I could not but ___ at his foolishness.
(a) laughing (b) to laugh (c) laugh (d) laughed
Answer: (c) laugh
Explanation: "Cannot/could not but" is followed by a bare infinitive.
42. By the age of four, the child ___ read simple words.
(a) could (b) was able (c) can (d) might
Answer: (a) could
Explanation: "Could" expresses general ability over a period in the past.
43. You ___ have warned us about the danger, but you said nothing.
(a) must (b) could (c) needn't (d) shall
Answer: (b) could
Explanation: "Could have + V3" expresses a past unrealised possibility/reproach.
44. We ___ swim in this river for hours every summer, and I owned a small boat too.
(a) would; would own (b) used to; used to own (c) would; used to own (d) used to; would own
Answer: (c) would; used to own
Explanation: Repeated action allows "would", but the state "own" requires "used to".
45. He ___ be very rich; he drives an old car and lives modestly.
(a) must (b) can't (c) should (d) may
Answer: (b) can't
Explanation: Present negative deduction uses "can't" (logical impossibility).
46. "You ___ not have spent so much," she said, looking at the pile of unused goods.
(a) should (b) need (c) must (d) can
Answer: (b) need
Explanation: "Needn't have + V3" = the spending was done but unnecessary.
47. Identify the error: "Hardly had he entered when the bell rings."
(a) Hardly had (b) he entered (c) when (d) the bell rings
Answer: (d) the bell rings
Explanation: The sequence requires the past tense "rang"; this tests modality/tense agreement around past narration.
48. I'd rather you ___ here until I return.
(a) stay (b) stayed (c) will stay (d) to stay
Answer: (b) stayed
Explanation: "Would rather + subject" takes the past subjunctive "stayed".
49. The witness ___ the accused, for he was blindfolded throughout.
(a) couldn't have seen (b) must have seen (c) should have seen (d) needn't have seen
Answer: (a) couldn't have seen
Explanation: Being blindfolded makes seeing impossible — "couldn't have + V3".
50. Choose the sentence with correct modal usage.
(a) She musts attend the class. (b) She need not to attend the class. (c) She ought to attend the class. (d) She used to attending the class.
Answer: (c) She ought to attend the class.
Explanation: "Ought to + bare infinitive" is correct; the others misuse "-s", "to" after "need not", and the "used to" form.