How to Use Modal Verbs in English: Can, Could, Should, Must, and More

Modal verbs are essential tools in the English language that express ability, possibility, necessity, permission, advice, and more. They are auxiliary verbs,

meaning they are used with the main verb to modify its meaning. Understanding how to use modal verbs correctly is crucial for achieving fluency and making your speech more natural and precise. In this guide,

we’ll explore the most common modal verbs — can, could, should, must, may, might, and others — and provide examples, explanations, and exercises to help you master their usage.

Modal verbs are a type of auxiliary verb that help express different meanings, such as:

Ability

Permission

Possibility

Obligation

Advice

Prohibition

Modal verbs do not change according to the subject and are always followed by the base form of the main verb (without “to,” except for ought to).

Can: Ability, permission

Could: Past ability, polite requests, possibility

Should: Advice, recommendation

Must: Necessity, strong recommendation, obligation

May: Permission, possibility

Might: Possibility (less certain than may)

Will: Future predictions, promises, willingness

Would: Polite requests, hypothetical situations

a. Can

Can is used to express:

Ability (present/future)

Example: I can swim.

Permission (informal)

Example: Can I use your phone?

Possibility

Example: It can get very hot in the desert.

Negative form: Cannot (can’t)

Example: He can’t drive yet.

b. Could

Could is the past tense of can and has several uses:

Past ability

Example: When I was younger, I could run faster.

Polite requests or offers

Example: Could you help me with my homework?

Possibility

Example: It could rain later today.

Hypothetical situations (conditional)

Example: If I had more time, I could travel around the world.

Negative form: Could not (couldn’t)

Example: She couldn’t attend the meeting yesterday.

c. Should

Should is used to:

Give advice or recommendations

Example: You should study for the test.

Express expectation or obligation

Example: She should arrive by 6 PM.

Express a polite suggestion

Example: You should try the new restaurant.

Negative form: Should not (shouldn’t)

Example: You shouldn’t skip meals.

d. Must

Must expresses:

Strong necessity or obligation

Example: You must wear a helmet while riding a bike.

Strong recommendation

Example: You must see that movie — it’s amazing!

Deduction or certainty (something is definitely true)

Example: She must be at home; I can see her car outside.

Negative form: Must not (mustn’t)

Example: You mustn’t smoke in this area.

e. May

May is used for:

Permission (formal)

Example: May I leave early today?

Possibility (less certain than “can”)

Example: It may snow tomorrow.

Requests (polite)

Example: May I borrow your pen?

Negative form: May not

Example: You may not enter without an invitation.

f. Might

Might is used for:

Possibility (less certain than may)

Example: She might come to the party later.

Suggestions (less direct than should)

Example: You might want to reconsider your decision.

Negative form: Might not

Example: I might not be able to attend the meeting tomorrow.

g. Will

Will is used for:

Future predictions or actions

Example: I will call you tomorrow.

Promises or offers

Example: I will help you with that project.

Willingness

Example: I will do the work if you ask me.

Negative form: Will not (won’t)

Example: He won’t agree to the plan.

h. Would

Would is the past tense of will and is used for:

Polite requests or offers

Example: Would you like some coffee?

Hypothetical situations or conditions

Example: If I were rich, I would travel the world.

Past habitual actions

Example: When we were kids, we would play outside all day.

Negative form: Would not (wouldn’t)

Example: I wouldn’t recommend that restaurant.

Modal verbs are often used to form questions, especially when you need to ask about ability, permission, possibility, or obligation.

Examples

Can you help me with this task?

Could you please pass the salt?

Should I bring a gift to the party?

Must we complete this today?

May I leave early?

Might she come to the event?

Practice Exercises

You __________ (can / must) take an umbrella. It looks like it’s going to rain.

I __________ (could / might) go to the gym later if I feel better.

She __________ (should / could) study harder for the exam.

We __________ (will / may) travel to Paris next year.

You __________ (must / might) not park in this area; it’s a no-parking zone.

Answers:

must

might

should

will

must

__________ you help me with this problem? (Can / Should)

I __________ speak three languages. (Can / Must)

You __________ be quiet in the library. (may / must)

We __________ be careful when walking on the icy road. (should / will)

__________ I leave early today? (May / Can)

Answers:

Can

must

should

May

Key Takeaways

Modal verbs are essential in English for expressing a wide range of meanings, including ability, possibility, necessity, permission, advice, and more.

Each modal verb has specific uses, so understanding how and when to use them is key to speaking and writing correctly.

Modal verbs do not change according to the subject and are always followed by the base form of the main verb.

Practice using modal verbs in questions, statements, and negative forms to become more confident in your English skills.

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