Introduction
Modal verbs are an important part of English grammar. We use them to express ability, give advice, ask for permission, describe obligations, and talk about possibilities.
In this lesson, you’ll learn how to use can, could, should, must, have to, may, and might in everyday conversations.
What Are Modal Verbs?
Modal verbs are helping verbs that change the meaning of the main verb in a sentence.
They help us express different ideas, including:
- Ability: What someone is able to do.
- Advice: What someone thinks is a good idea.
- Obligation: What someone is required to do.
- Permission: What someone is allowed to do.
- Possibility: What might happen or be true.
Examples:
- She can speak three languages.
- You should check your email.
- Employees must follow safety rules.
- It might rain tomorrow.
How Do We Form Sentences with Modal Verbs?
Most modal verbs are followed by the base form of the main verb, without to.
Subject + Modal Verb + Base Verb
Examples:
- She can drive.
- They should leave early.
- We might visit tomorrow.
Negative sentences:
Add not after the modal verb.
- He cannot (can’t) swim.
- You should not (shouldn’t) worry.
- They might not attend.
Questions:
Place the modal verb before the subject.
- Can you help me?
- Should we leave now?
- Could you repeat that?
Important: Modal verbs do not change according to the subject.
- Correct: She can speak English.
- Incorrect: She cans speak English.
Exception: We use have to with I, you, we and they, but has to with he, she and it.
- I have to work.
- She has to work.
CAN and COULD — Ability
We use can to describe someone’s ability in the present.
Examples:
- I can use different computer programmes.
- My sister can play the piano.
- He can solve difficult problems.
We use could to describe a general ability someone had in the past.
Examples:
- When I was younger, I could run very fast.
- She could read before she started school.
- My grandfather could speak five languages.
Remember:
- CAN → Present ability
- COULD → General past ability
Note: For a specific successful action in the past, we often use was/were able to rather than could.
Example: Despite the traffic, we were able to arrive on time.
SHOULD — Advice and Recommendations
We use should when giving advice, making recommendations, or expressing what we think is a good idea.
Examples:
- You should drink more water.
- He should prepare for his interview.
- We should leave earlier to avoid traffic.
We use shouldn’t when advising someone not to do something.
Examples:
- You shouldn’t spend too much time looking at your phone.
- She shouldn’t ignore the warning signs.
- They shouldn’t make decisions without enough information.
Remember: SHOULD expresses advice or recommendations, not a strict obligation.
MUST and HAVE TO — Obligation and Necessity
We use must and have to when something is necessary or required.
MUST
We often use must to express strong obligations, rules or requirements.
Examples:
- Passengers must wear seat belts.
- Visitors must show identification.
- You must follow the instructions carefully.
HAVE TO
We commonly use have to when an obligation comes from an external rule, requirement or situation.
Examples:
- I have to renew my passport.
- She has to attend a meeting tomorrow.
- We have to submit the application before Friday.
Both must and have to can express obligation, and they are often interchangeable.
CAN, COULD and MAY — Permission
We use can, could and may when asking for or giving permission.
CAN
Used for everyday requests and permission.
Examples:
- Can I borrow your pen?
- You can leave your bag here.
COULD
Used to make a polite request for permission.
Examples:
- Could I use your computer for a moment?
- Could we leave a little earlier?
MAY
Used for more formal or polite requests for permission.
Examples:
- May I ask a question?
- May I come in?
Remember:
MAY → More formal
- CAN → Common and informal
- COULD → Polite
- MAY → More formal
MAY and MIGHT — Possibility
We use may and might when something is possible but not certain.
MAY
Examples:
- The company may open a new office.
- She may arrive later than expected.
- We may need more information.
MIGHT
Examples:
- I might change my plans.
- They might cancel the event.
- It might be difficult to find parking.
Both modal verbs express uncertainty. Might can sometimes suggest a lower degree of certainty, but the difference is often small.
Remember: MAY and MIGHT describe possibilities, not definite outcomes.
| Modal verb | Main use | Example |
| Can | Present ability | I can speak French. |
| Could | Past ability | I could swim when I was six. |
| Should | Advice | You should take a break. |
| Must | Strong obligation | You must wear a helmet. |
| Have to | Necessity | I have to finish this report. |
| Can | Permission | Can I sit here? |
| Could | Polite permission request | Could I open the window? |
| May | Formal permission | May I enter? |
| May | Possibility | It may snow tonight. |
| Might | Possibility | She might join us later. |
Speaking Practice
Create your own sentences using each of the following modal verbs.
| Can | Could | Should |
| Must | Have to | Might |