What is "can"?
Can is a modal verb. A modal verb = a helping verb that adds a meaning, like ability or permission, to the main verb. We use can to say that someone is able to do something, or that something is allowed. The negative is can't (cannot).
I can swim, but I can't ski.
How to form "can": can + base verb
The base verb = the verb with no "to" and no "-s" (swim, drive, speak).
Positive
| Subject | Can | Base verb | Example |
|---|---|---|---|
| I / you / we / they | can | speak | I can speak French. |
| he / she / it | can | drive | She can drive. |
Can is the same for every subject. There is no "-s": he can, not he cans.
Negative
| Full form | Short form | Example |
|---|---|---|
| cannot | can't | I can't cook. |
| cannot | can't | He cannot come today. |
- Cannot is one word.
- Can't is more common in speaking and friendly writing.
Questions
Put can before the subject.
| Can | Subject | Base verb | Example |
|---|---|---|---|
| Can | you | swim | Can you swim? |
| Can | she | come | Can she come to the party? |
| Can | I | sit | Can I sit here? |
With question words, the question word goes first:
- What can you see?
- Where can I park?
- When can you start?
Short answers
| Question | Yes | No |
|---|---|---|
| Can you drive? | Yes, I can. | No, I can't. |
| Can he speak English? | Yes, he can. | No, he can't. |
| Can we go now? | Yes, you can. | No, you can't. |
When to use "can"
1. Ability: what you are able to do
- I can play the guitar.
- My son can read now. He's five.
- She can't swim.
- Can you speak Spanish?
2. Permission: what is allowed
- Can I use your phone? → Yes, of course you can.
- You can park here after 6 pm.
- You can't smoke in the building.
- Students can use the library on Saturdays.
3. Requests: asking someone to do something
- Can you help me, please?
- Can you open the window?
- Can I have a coffee, please?
Could is a little more polite: Could you help me, please?
4. Possibility: what is possible
- You can buy tickets online.
- It can be very cold in Winnipeg in January.
- We can meet tomorrow if you like.
- You can't get there by train.
Could: past ability
For ability in the past, use could / couldn't + base verb.
| Present | Past |
|---|---|
| I can swim. | I could swim when I was six. |
| She can't sleep. | She couldn't sleep last night. |
| Can you see it? | Could you see it? |
More examples:
- My grandmother could speak four languages.
- I couldn't find my keys this morning.
Can vs be able to
Be able to has the same meaning as can for ability. Can is more common in the present.
| Can | Be able to |
|---|---|
| I can swim. | I am able to swim. (more formal) |
| — | I will be able to drive next year. |
| — | I'd like to be able to cook. |
Can has no "-ing" form, no "to" form and no future form. In these cases, use be able to:
- Wrong:
I will can come.→ Correct: I will be able to come. - Wrong:
I want to can dance.→ Correct: I want to be able to dance.
For more, see Modal Verbs.
How to pronounce "can" and "can't"
It is easy to confuse can and can't in speech, so listen carefully.
| Word | How it sounds | Example |
|---|---|---|
| can (in a sentence) | short and weak: /kən/ | I can swim. → "I kən swim" |
| can (stressed, short answer) | strong: /kæn/ | Yes, I can. |
| can't (British) | long "ah": /kɑːnt/ | I can't swim. |
| can't (North American) | like "can" + t: /kænt/ | I can't swim. |
Tip: can't is usually stressed, and can in the middle of a sentence is usually not stressed. Also listen for the "t" at the end of can't; it is often very short or hard to hear, so the stress helps you more.
Common mistakes
1. Adding "to" after can
- Wrong:
I can to swim. - Correct: I can swim.
- Can + base verb, with no "to".
2. Adding "-s" to can or the verb
- Wrong:
She cans drive./She can drives. - Correct: She can drive.
- No "-s" on can and no "-s" on the main verb.
3. Using "do" in questions and negatives
- Wrong:
Do you can help me?/I don't can come. - Correct: Can you help me? / I can't come.
- Can makes its own questions and negatives.
4. Writing "can not" as two words
- Usual: I cannot come. / I can't come.
- "Can not" (two words) is rare. Use cannot or can't.
5. Using "can" for the future with "will"
- Wrong:
I will can help you tomorrow. - Correct: I can help you tomorrow. / I will be able to help you tomorrow.
- Never use two modal verbs together.
Quick reference
| Present | Past | |
|---|---|---|
| Positive | I can swim. | I could swim. |
| Negative | I can't / cannot swim. | I couldn't swim. |
| Question | Can you swim? | Could you swim? |
| Short answer | Yes, I can. / No, I can't. | Yes, I could. / No, I couldn't. |
Common questions
Is it "cannot" or "can not"?
Write cannot (one word) or can't. "Can not" as two words is rare, so it is safer to use cannot or can't in your writing.
Is "can I" or "may I" correct?
Both are correct. May I ...? is more formal and polite. Can I ...? is more common in everyday English: Can I sit here?
What is the past of "can"?
For ability in the past, use could: I could read when I was four. For one specific success in the past, people often use was able to or managed to: I was able to fix the car.
Practise next
- Modal Verbs — could, may, must, should and more
- B1 Modal Verbs Quiz — test can, could and other modals
- Verb To Be: Am, Is, Are — another verb with no "do" in questions
- Present Simple — questions with do and does