can, can't

Can has one form for every subject. The verb after it is the base form, with no to and no -s.

The negative is can't, or cannot in formal writing (one word). In questions, can comes before the subject.

Ability

Use can for things you know how to do, or are able to do.

Permission

Can also asks for permission or gives it, and can't says that something is not allowed.

Asking someone to do something

Can you …? asks for help. Could you …? is a little more polite.

Saying can and can't

In a sentence, can is short and weak, like "kn": I can swim sounds like "I kn SWIM". Can't is always strong, so the difference is clear. In British English it sounds like "kahnt"; in American English, like "kant".

For the past, use could: I could swim when I was five.

Common mistakes

• × She cans swim. → She can swim.
• × I can to swim. → I can swim.
• × He can swims. → He can swim.
• × Do you can swim? → Can you swim?
• × I don't can come. → I can't come.