Modal Verbs Exercises
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How modal verbs work
Modal verbs (can, could, may, might, must, should, will, would) add meaning like ability, permission, obligation or probability to another verb — and they follow special grammar rules.
- Form:
- modal + base verb: She can swim (never 'to swim' or 'swims')
- No -s / no do:
- He must go (not 'musts'); negatives and questions without 'do': Can you…? You shouldn't…
- Ability:
- can / could: I can drive. She could read at age four.
- Obligation:
- must / have to: You must wear a seatbelt. | Prohibition: mustn't
- Advice:
- should / shouldn't: You should see a doctor.
- Possibility:
- may / might / could: It might rain later.
Examples
She can speak three languages fluently.
ability
You must fasten your seatbelt during take-off.
strong obligation (rule)
You shouldn't drink so much coffee before bed.
negative advice
It might snow tonight, so drive carefully.
possibility, not certain
May I use your phone for a minute?
polite permission
Practice exercises
Choose the correct modal
Select the modal verb that best fits each situation.
1.You ___ smoke in the hospital — it's strictly forbidden.
2.I ___ ride a bike when I was five years old.
3.You look exhausted. You ___ take a day off.
4.It's a holiday tomorrow, so I ___ get up early.
5.Take an umbrella — it ___ rain this afternoon.
6.You've been working non-stop since 7 a.m. — you ___ be exhausted!
Complete the sentences
Type the missing modal verb (can, can't, must, mustn't, should, shouldn't, might...).
Put the words in order
Click the words in the correct order to build the sentence.
13. Build the sentence:
14. Build the sentence:
15. Build the sentence:
16. Build the sentence:
True or false?
Decide if each statement about modal verbs is true or false.
17."She cans speak Italian" is correct English.
18.'Mustn't' and 'don't have to' mean the same thing.
19.After a modal verb, we use the base form of the verb without 'to'.
20.'Might' expresses a smaller probability than 'will'.
Modal verbs explained in depth
Modal verbs are small words with big responsibilities. With a single syllable, English speakers signal whether something is possible, necessary, allowed, forbidden or advisable. Because so much social meaning is packed into them — politeness, authority, doubt — using the wrong modal doesn't just sound ungrammatical; it can sound rude or change what you're saying entirely.
Grammatically, modals form a closed club with strict rules: no third-person -s, no infinitive 'to' after them, no combining with 'do' in questions and negatives, and no past participle forms. This is actually good news for learners — once you internalise 'modal + base verb', the mechanics never change. All the difficulty lives in choosing the right modal for the meaning.
The meaning map has three main territories. Ability and permission belong to can/could/may: 'I can swim' (ability), 'Could I leave early?' (permission). Obligation belongs to must and have to, with the crucial negative asymmetry that trips up almost every learner: 'You mustn't tell anyone' forbids telling, while 'You don't have to tell anyone' merely makes telling optional. Probability belongs to may/might/could for possibility and must/can't for logical deduction: 'She must be home — her lights are on.'
'Should' deserves its own mention as the advice modal. It is softer than must, which is why doctors, teachers and friends reach for it constantly: 'You should rest.' Its negative, 'shouldn't', warns without forbidding. In formal writing, 'ought to' is an equivalent, though far less common.
When practising, focus on contrasting pairs in context: mustn't vs don't have to, can vs might, should vs must. The exercises on this page are built around exactly those contrasts, because choosing between two similar modals — not forming them — is where real-world mistakes happen.
Frequently asked questions
What are the modal verbs in English?
The core modal verbs are can, could, may, might, must, shall, should, will and would. Semi-modals like have to, ought to and need to behave similarly in meaning but not always in grammar.
What is the difference between 'must' and 'have to'?
Both express strong obligation and are often interchangeable. 'Must' tends to express the speaker's own authority or urgency (I must finish this today), while 'have to' points to external rules (I have to wear a uniform at work). The key contrast is in the negative: 'mustn't' = forbidden, 'don't have to' = not necessary.
Why can't I say 'She cans' or 'He musts'?
Modal verbs are grammatically fixed: they never take -s, never use 'do' for questions or negatives, and are always followed by the base form of the main verb. That's what makes them 'modals' rather than normal verbs.
What is the difference between 'may', 'might' and 'could' for possibility?
All three express present or future possibility and are close in meaning. 'Might' often suggests slightly less certainty than 'may'; 'could' emphasises that something is one of several possibilities. In everyday speech they are largely interchangeable.
How do I make questions with modal verbs?
Invert the modal and the subject — no 'do' needed: Can you drive? Should we wait? May I come in? The main verb stays in its base form.
Answer key
1. You ___ smoke in the hospital — it's strictly forbidden.
Answer: mustn't
'Mustn't' expresses prohibition. 'Don't have to' means it's not necessary — a very different meaning.
2. I ___ ride a bike when I was five years old.
Answer: could
'Could' is the past form of 'can' for general ability in the past.
3. You look exhausted. You ___ take a day off.
Answer: should
'Should' gives advice or a recommendation.
4. It's a holiday tomorrow, so I ___ get up early.
Answer: don't have to
'Don't have to' = it's not necessary. 'Mustn't' would mean getting up early is forbidden.
5. Take an umbrella — it ___ rain this afternoon.
Answer: might
'Might' expresses a possibility that is not certain.
6. You've been working non-stop since 7 a.m. — you ___ be exhausted!
Answer: must
When we draw a logical conclusion from evidence (long hours of work), we use 'must': you must be exhausted. 'Can't' would express the opposite deduction; 'might not' means 'perhaps not' — too weak for the obvious conclusion.
7. ___ you help me carry these boxes, please?
Answer: can
Requests use can/could/will/would — 'could' and 'would' are the more polite options.
8. In most countries, drivers ___ wear a seatbelt — it's the law.
Answer: must
Legal obligations take 'must' or 'have to'.
9. You ___ eat so much sugar — it's bad for your teeth.
Answer: shouldn't
Advice against something uses 'shouldn't'.
10. I'm not sure where Anna is. She ___ be at the gym.
Answer: might
Uncertain possibility about the present: might/may/could + be.
11. Sorry, I ___ come to the party on Saturday — I'm working.
Answer: can't
'Can't' expresses inability or impossibility.
12. Visitors ___ bring food or drinks into the museum.
Answer: mustn't
A rule forbidding something uses 'mustn't' (or 'can't'). 'Don't have to' would mean bringing food is optional — the opposite of a ban.
13. swim / she / can / very well
Answer: she can swim very well
Subject + modal + base verb + adverbial.
14. I / your pen / may / borrow / ?
Answer: may I borrow your pen ?
Modal questions invert the modal and the subject: May I…?
15. be / you / late / shouldn't / for class
Answer: you shouldn't be late for class
Subject + modal negative + base verb.
16. must / a visa / travelers / get / before the trip
Answer: travelers must get a visa before the trip
Subject + must + base verb + object + time phrase.
17. "She cans speak Italian" is correct English.
Answer: False
False — modal verbs never take -s: "She can speak Italian."
18. 'Mustn't' and 'don't have to' mean the same thing.
Answer: False
False — 'mustn't' means it is forbidden; 'don't have to' means it is not necessary.
19. After a modal verb, we use the base form of the verb without 'to'.
Answer: True
True — She must go, You can leave. (Exception: 'have to' and 'ought to' contain 'to' themselves.)
20. 'Might' expresses a smaller probability than 'will'.
Answer: True
True — 'It will rain' is a confident prediction; 'It might rain' is only a possibility.