Updated on October 22, 2025

Modal Verb Can

Can is a modal verb that we use to talk about ability, permission, and possibility. It always goes before the main verb and is followed by the base form of the verb (without to).

Table of Contents

Exercises

Explanation

Modal Verb: Can

Can is a modal verb. We use can to talk about:

  • ability (what someone is able to do)

  • permission (when something is allowed)

  • possibility (when something is possible)

  • requests (when we ask politely)

Forms

Tense

Form

Example

Present

can

I can swim.

Past

could

I could swim when I was five.

Future

will be able to

I will be able to swim next summer.

Ability

Use can or could to talk about skills or things you know how to do.
I can speak English.
She can play the guitar.
When I was a child, I could run very fast.

Permission

Use can or could to ask or give permission.

Examples: 
Can I go out now?

Could I use your phone, please? (more polite)
You can take my book.
You can’t park here.

Possibility

Use can to talk about what is possible.

Examples: 
It can be cold in winter.
People can get sick if they don’t sleep well.
That story can’t be true! (negative = not possible)

Requests

Use can or could to ask someone to do something.

Examples: 
Can you help me, please?
Could you close the window? (more polite)

Negative Forms

Form

Contraction

Example

cannot

can’t

I can’t drive a car.

could not

couldn’t

I couldn’t swim last year.

Special Phrases

I can’t help laughing! → I can’t stop laughing.
I can’t but agree. → I must agree.
I can’t possibly do it. → It’s impossible for me to do it.

Be able to

We use be able to instead of can when we need to speak about the future or a specific situation.

Examples: 
I’m able to meet you today.
I was able to finish my project yesterday.
I will be able to travel next year.

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