What are modal verbs and how are they used?

Modal verbs (can, could, should, must, might, may) are auxiliary verbs that express ability, permission, advice, obligation, or possibility. They're always followed by the base form of the main verb without 'to'.

What is the difference between 'must' and 'have to'?

'Must' expresses personal obligation or strong recommendation from the speaker, while 'have to' expresses external obligation or rules. Compare: 'I must study harder' (personal decision) vs 'I have to wear a uniform' (it's a rule).

When should I use 'can' versus 'could'?

'Can' is used for present ability and informal permission. 'Could' is used for past ability, polite requests, and possibilities. For example: 'Can you swim?' (ability) vs 'Could you help me, please?' (polite request).

What is the difference between 'might' and 'may'?

Both express possibility. 'May' is slightly more formal. 'It may rain.' 'It might rain.' 'May' is also used for formal permission. 'May I leave the room?' In everyday English, 'might' is more common for possibility.

How do I make negative sentences with modals?

Add 'not' after the modal: 'cannot/can't', 'should not/shouldn't', 'must not/mustn't'. 'Mustn't' means it is forbidden. 'You mustn't smoke here.' 'Don't have to' means no obligation.

What is the difference between 'should' and 'ought to'?

They are similar for advice. 'Ought to' is slightly more formal and less common. 'You should see a doctor.' = 'You ought to see a doctor.' The negative is 'ought not to' but is rare; 'shouldn't' is more natural.

How do I use 'could' to express possibility?

Use 'could' for future possibility, especially when it's less certain. 'It could snow tomorrow.' 'She could be at home.' It's similar to 'might' and is not about ability in this case.

What does 'must' mean for deductions?

Use 'must' to express a logical conclusion or strong certainty. 'You've been traveling all day. You must be tired.' (I am sure you are tired). The opposite is 'can't': 'He can't be at home; his car isn't here.'

CEFR A2

Modal Verbs

Master the special verbs that express ability, permission, advice, and obligation. Learn to use can, could, should, must, have to, might, and may correctly.

Master Modal Verbs

What You Will Learn

Modal verbs are special helping verbs that express ability, permission, advice, obligation, and possibility. Master these essential verbs to make your English more precise and natural.

Express ability with can and could

Give advice with should and ought to

Show obligation with must and have to

Express possibility with might and may

Understand the key differences between similar modals

What Are Modal Verbs?

CAN = present ability. COULD = past ability or polite requests. MIGHT/MAY = possibility (maybe).

I can swim. (ability)She could drive at 18. (past)It might rain. (possibility)May I sit down? (permission)

Modal rules

All modals: same form for all subjects (no -s). Always followed by base verb. No do/does in questions — move the modal to front. No infinitive or gerund after modals.

Modal verbs are helping verbs that add meaning to the main verb. They show things like ability, permission, advice, obligation, and possibility. Unlike regular verbs, they have special rules.

Special Characteristics

• No "s" for he/she/it: He can swim (not "He cans swim")

• No "to" after modals: I must go (not "I must to go")

• Base form of main verb: She should study (not "She should studies")

• Form questions by inversion: Can you swim? (not "Do you can swim?")

Common Modal Verbs

• can, could - ability, permission

• should, ought to - advice

• must, have to - obligation

• might, may - possibility

• will, would - future, conditionals

📖 A Busy Day at Work

Tom can speak English and Spanish, so he can help international clients.

His boss says he must finish the report by 5 PM — it's an important deadline.

His colleague asks, "Could you check my presentation?" Tom should help, but he might not have enough time.

At lunch, Tom may go to the new café, or he could eat at his desk — he hasn't decided yet.

Modal verbs help us express what we can do, what we must do, and what might happen!

Key Rule: Modal Verb Structure!

Modal verbs are followed by the BASE FORM of the main verb (no "to", no "-s", no "-ing").

✓ Correct: I can swim. She must go. They should study.

✗ Incorrect: I can to swim. She must goes. They should studying.

Modal Verbs by Function

Learn which modal verbs to use for different purposes. Each function has its own set of appropriate modals.

Function	Modal Verbs	Examples
Ability	can, could, be able to	• I can speak French. • She could swim at age 5.
Permission	can, could, may	• Can I use your phone? • May I leave early?
Advice	should, ought to, had better	• You should see a doctor. • We ought to arrive early.
Obligation	must, have to, need to	• I must finish this work. • You have to wear a seatbelt.
Possibility	might, may, could	• It might rain tomorrow. • She may be late.
Prohibition	mustn't, can't	• You mustn't smoke here. • You can't park there.

Strong

must

have to

need to

For rules and strong obligations

Medium

should

ought to

For advice and recommendations

Weak

could

might

may

For possibilities and suggestions

Try It

Choose the correct modal verb for each function:

1. Expressing ability: __________

2. Giving advice: __________

3. Showing strong obligation: __________

4. Talking about possibility: __________

💡 💡 Check your answers

1. can / could (ability)

2. should / ought to (advice)

3. must / have to (obligation)

4. might / may / could (possibility)

Want to try a Modal Verbs quiz?

Practice with multiple choice questions

Key Differences Between Modal Verbs

Some modal verbs have similar meanings but different uses. Learn these important distinctions.

Must vs Have to

Must (internal obligation)

• I must study for my exam. (my decision)

• You must try this cake! (strong recommendation)

• She must be tired. (deduction - 95% sure)

Have to (external obligation)

• I have to work tomorrow. (boss requires it)

• You have to wear a seatbelt. (law requires it)

• We have to be at the airport by 6. (flight schedule)

Can vs Could

Can (present ability/permission)

• I can swim. (present ability)

• Can I borrow your pen? (informal permission)

• It can be cold in winter. (general possibility)

Could (past ability/polite requests)

• I could swim when I was five. (past ability)

• Could you help me? (polite request)

• It could rain later. (future possibility)

Strength Comparison

Should (advice)

You should exercise.

Good idea, not required

Have to (external rule)

You have to pay taxes.

External requirement

Must (internal/strong)

I must call my mother.

Personal obligation

Possibility: Might vs May vs Could

Might (~30% sure)

• I might go to the party.

• It might rain tomorrow.

May (~50% sure)

• The boss may be in a meeting.

• She may arrive late.

Could (~40% sure)

• We could visit Paris next year.

• He could be right.

Note: In everyday English, these are often used interchangeably for possibility.

Ready to test your Modal Verbs knowledge?

Challenge yourself with fill-in-the-blank exercises

Forming Sentences with Modal Verbs

Learn the correct sentence structures for positive sentences, negative sentences, and questions with modal verbs.

Positive Sentences

Subject + modal + base verb

• I can swim.

• She should study.

• They must arrive on time.

No "to", no "-s", no "-ing"

Negative Sentences

Subject + modal + not + base verb

• I cannot swim. / I can't swim.

• She should not go. / She shouldn't go.

• They must not be late. / They mustn't be late.

Use contractions in speaking

Questions

Modal + subject + base verb

• Can you swim?

• Should she study?

• Must they arrive early?

No "do/does/did" with modals

Important Rules

No Third Person -s

✓ He can speak French.

✗ He cans speak French.

✓ She must finish her work.

✗ She musts finish her work.

No "to" After Modals

✓ I should go now.

✗ I should to go now.

✓ They might arrive late.

✗ They might to arrive late.

Question Words with Modal Verbs

Question word + modal + subject + base verb

• What should I do?

• Where can we meet?

• When must you leave?

• How could she know?

• Why would he say that?

Real-Life Usage Examples

See how modal verbs are used in different everyday situations.

At Work & School 🏢

You must submit the report by Friday. (obligation)

We should review the data before the meeting. (advice)

I can help you with that presentation. (ability/offer)

Social Situations & Travel 🎉

Could you pass me the salt, please? (polite request)

We might go to the beach if the weather is nice. (possibility)

You have to try the local seafood! (strong recommendation)

Rules & Regulations 🚫

You mustn't use your phone during takeoff and landing. (prohibition)

Visitors have to show ID at the entrance. (external rule)

You can't park here between 8 AM and 6 PM. (not allowed)

Making Requests & Offers 🙋‍♀️

Can I borrow your pen? (informal request)

May I have your attention, please? (formal request)

Shall I help you with your bags? (offer - British English)

Would you like some coffee? (polite offer)

Common Mistakes

❌ I must to go now.

✓ I must go now.

No 'to' after modal verbs

❌ She cans speak French.

✓ She can speak French.

Modal verbs don't take -s for third person

❌ Do you can swim?

✓ Can you swim?

No 'do/does/did' with modal verbs in questions

❌ I don't must work tomorrow.

✓ I don't have to work tomorrow.

Use 'don't have to' for lack of obligation, not 'don't must'

❌ He should to study more.

✓ He should study more.

No 'to' after should

❌ You must see a doctor. (external rule from doctor)

✓ You have to see a doctor.

Use 'have to' for external obligations, 'must' for personal obligations

❌ I can to help you.

✓ I can help you.

No 'to' after can

❌ They are must finish the project.

✓ They must finish the project.

No 'be' verb before modal verbs

Master Modal Verbs sentence building!

Drag and drop words to form correct sentences

Practice Tips

Remember the golden rule: Modal verb + BASE FORM (no "to", no "-s", no "-ing")

Practice by function: make lists of sentences for ability, permission, advice, obligation, possibility

Pay attention to the difference between must (personal obligation) and have to (external obligation)

Use could for polite requests and can for informal ones

Practice negative forms: can't, shouldn't, mustn't, don't have to (different meanings!)

Listen to native speakers in movies or podcasts to hear natural modal verb usage

Use the speaking practice section to work on your pronunciation and fluency with modal verbs

Create real-life scenarios: What would you say at work? In a restaurant? At the airport?

Speaking Practice

To practice your pronunciation, listen to the native speaker audio first. Then 'Record' yourself repeating what you heard, then use the 'Playback' button to compare your pronunciation with the native speaker. If you want to record yourself again, simply click 'Delete'!

I can speak three languages fluently.

You should visit the doctor if you feel sick.

We must finish this project by Friday.

She might come to the party tonight.

He has to wear a uniform at work.

Could you please pass me the salt?

They may arrive late because of traffic.

You mustn't smoke in this building.

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