Can, can’t – ability, possibility, permission

Can and can’t are modal verbs used to express ability, possibility, and permission. They are very common in everyday English and are easy to use once you understand their rules.

1. Expressing Ability

We use can to talk about skills or abilities:

• I can swim. (I have the ability to swim.)
• She can speak three languages. (She has the skill to speak them.)

We use can’t to say that someone does not have the ability:

• I can’t drive a car. (I don’t know how to drive.)
• He can’t dance. (He is not able to dance.)
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2. Talking About Possibility

Use can to describe things that are possible:

• You can find the book in the library. (It is possible to find it there.)
• We can arrive before 8 PM if we leave now. (It is possible to arrive on time.)

Use can’t to talk about things that are not possible:

• You can’t see stars during the day. (It’s impossible.)
• She can’t be at home now; I just saw her at the park. (It’s not possible.)
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3. Asking for and Giving Permission

We use can to ask for and give permission:

• Can I borrow your book? (Asking for permission)
• Yes, you can. (Giving permission)

We use can’t to refuse permission:

• You can’t go outside now. (Refusing permission)
• Sorry, you can’t use my phone. (Refusing permission)
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Quick Tips

• Can is always followed by the base form of the verb (e.g., can swim, not can swims).
• Can’t is the contraction of cannot and is more common in spoken English.