Can: ability and permission

Can is one of the most useful small words in English. It lets you say what you're able to do — like swim or speak French — and also what you're allowed to do, like leave early or use the phone. Same word, two related jobs.

Quick shortcut: can + the base form of the verb, with no to and no change for he/she/it. She can swim, not ❌ She can to swim or ❌ She cans swim.

Can: the basic form

Can works the same way for every subject — no extra -s for he/she/it, unlike most present simple verbs:

• I can swim.
• She can play the guitar.
• They can speak English.

The verb after can is always in its base form, with no to: ✅ He can drive, never ❌ He can to drive or ❌ He can drives.

Questions and negatives — no "do" needed

Like be, can doesn't use do/does to make questions or negatives. In questions, can simply moves in front of the subject:

• ✅ Can you swim? — never ❌ Do you can swim?
• ✅ Can she drive?
• Can they come to the party?

The negative form is cannot. In speaking and informal writing, we usually use the contraction can't:

• ✅ I can't swim. — never ❌ I don't can swim.
• He can't come today.
• We can't find the keys.

Ability: what you're able to do

The most common use of can is talking about a skill or ability — something you know how to do or are physically able to do:

• I can ride a bike.
• She can speak three languages.
• He can't cook very well.
• Can you swim?

Permission: what you're allowed to do

Can also asks for or gives permission — saying what's allowed:

• You can sit here. (= it's allowed)
• Can I open the window? (= is it allowed?)
• You can't park here. (= it's not allowed)
• Can we leave early today?

Can you...? is also a very common way to make a polite everyday request, not just to ask about ability: Can you help me? really means "please help me," not "are you able to help me?"

You can also use may to ask for permission (May I open the window?), which sounds a little more formal or polite — but can is by far the more common choice in everyday English, and is perfectly polite on its own.

Short answers

In short answers, just repeat can or can't after the subject:

• Can you swim? — Yes, I can. / No, I can't.
• Can she drive? — Yes, she can. / No, she can't.

Beyond "can"

The modal verb can doesn't have forms like to can, canning, or canned for ability or permission. For now, learn can for simple present ability and permission — other forms, like could for the past and be able to for the future or after other verbs, are useful later (their own topic, coming soon).

Common mistakes

• ❌ She can to swim. → ✅ She can swim. (never to after can)
• ❌ He cans drive. → ✅ He can drive. (no -s, even for he/she/it)
• ❌ I don't can swim. → ✅ I can't swim. (the negative is can't, not don't can)
• ❌ Do you can swim? → ✅ Can you swim? (no do/does with can)
• ❌ I can swimming. → ✅ I can swim. (base form, not -ing)
• ❌ Can I to use your phone? → ✅ Can I use your phone? (still no to, even in permission questions)

Quick check

Which form fits?

1. She ____ speak Japanese. (can / cans)
2. ____ you help me? (Can / Do can)
3. He ____ come to the party. (can't / don't can)
4. I can ____ a bike. (ride / to ride)

Key takeaways

• Can doesn't change for he/she/it — no extra -s.
• The verb after can is always the base form, with no to.
• Questions and negatives don't use do/does: Can you...? / can't.
• Can covers both ability (I can swim) and permission (Can I sit here?) — for the past, future, or after other verbs, could or be able to take over.