Sofia is in her first guitar lesson. Her teacher asks: "Can you play any chords?" Sofia answers: "I can play C and G, but I can't play F yet." One small word does three jobs. It tells you what someone is able to do, and what they aren't.
Can is the most common modal verb in English. It expresses three different ideas: ability, possibility, and permission. The form stays the same for all three.
Practise this topic: when you finish reading, try the interactive
can / can't exercises at the top of this page.
Can is a modal verb. That means it works differently from normal verbs. Three rules tell you everything.
Rule 1: No -s with he, she, it.
She can swim. ✗ She cans swim.
Rule 2: No to after can. The verb that follows is in its base form.
I can drive. ✗ I can to drive.
Rule 3: No do/does in negatives or questions. Can changes its own position.
Can you swim? ✗ Do you can swim?
| Positive |
Negative |
Question |
| I can swim. |
I can't swim. |
Can I swim? |
| She can cook. |
She can't cook. |
Can she cook? |
| We can help. |
We can't help. |
Can we help? |
The form does not change for any subject: I, you, he, she, it, we, they all use can and can't.
Can't and cannot
Both are correct. They mean exactly the same thing.
- Can't — short form, used in speaking and informal writing.
- Cannot — full form, used in formal writing. It is one word, not two.
Cannot is written as one word. can not is rare and often a mistake. Use cannot in formal writing and can't everywhere else.
Use 1: Ability (what you know how to do)
This is the most common use. Can describes a skill or something you have learned to do.
- Lucas can ride a bike.
- My grandmother can speak four languages.
- I can't play the piano.
- Can your son swim?
You also use can for things you are physically able to do right now:
- I can see the mountains from here.
- She can't hear you — the music is too loud.
Use 2: Possibility (what is possible)
Can also tells you that something is possible — not certain, just possible.
- It can be very cold in Moscow in January.
- This bag can hold ten kilos.
- You can buy tickets at the station.
- Tomatoes can be red, yellow, or green.
The negative can't means "it is not possible" or "it is impossible":
- You can't see the sun at midnight in summer.
- This phone can't work without a battery.
Use 3: Permission (asking and giving)
Use can to ask if something is allowed, or to say that it is.
| Asking |
Answering |
| Can I open the window? |
Yes, you can. / No, you can't. |
| Can we use our phones in class? |
No, you can't. |
| Can I have a glass of water, please? |
Of course you can. |
You also use can to ask someone politely to do something. This is a request:
- Can you help me, please?
- Can you pass the salt?
- Can you wait a minute?
Could is more polite than
can for requests and asking permission:
Could you help me, please? You will study
could at A2 — see
can, could, should.
Short answers
You don't repeat the main verb. Use can or can't alone.
| Question |
Yes |
No |
| Can you swim? |
Yes, I can. |
No, I can't. |
| Can Maria cook? |
Yes, she can. |
No, she can't. |
| Can your dog do tricks? |
Yes, it can. |
No, it can't. |
Don't say Yes, I can swim as a short answer — it sounds heavy and unnatural. Just say Yes, I can.
Pronunciation
Can and can't sound different in normal speech, but the difference can be hard to hear.
- Can in a positive sentence is usually weak: /kən/. The vowel is short and quiet. I can swim sounds like "I k'n swim."
- Can't is strong and stressed: /kɑːnt/ in British English, /kænt/ in American English. The vowel is loud and clear.
- If you don't hear a clear vowel, the speaker probably said can, not can't.
Common mistakes
1. Adding -s for he, she, it.
He cans drive. → He can drive.
Modal verbs never take -s. The form is the same for every subject.
2. Adding to after can.
I can to speak French. → I can speak French.
After can, use the base form of the verb without to.
3. Using do or does in questions.
Does she can swim? → Can she swim?
Can moves to the front by itself. No helping verb is needed.
4. Adding -ing after can.
I can swimming. →
I can swim.
Use the base form, not the
-ing form. Compare with the
present continuous, where you do use
-ing.
5. Writing cant without an apostrophe.
I cant come. → I can't come.
The short form needs an apostrophe between n and t.
Frequently asked questions
What is the difference between can and can't?
Can is positive. It means "is able to" or "is allowed to." Can't is the short form of cannot, the negative. It means "is not able to" or "is not allowed to." For example: I can drive a car, but I can't drive a truck. Both forms are used for ability, possibility, and permission.
Do you say can or can to?
You say can, never can to. After can, the next verb is in its base form with no to. Say I can speak Italian, not I can to speak Italian. This is true for all modal verbs in English.
Can he cans? Why is it always just can?
Modal verbs in English never take an -s ending, even with he, she, or it. So you say He can swim, not He cans swim. The same rule applies to could, will, would, must, may, and other modals. The form is identical for every subject.
What is the difference between can't and cannot?
They mean exactly the same thing; only the style is different. Can't is the short form, used in everyday speech and informal writing. Cannot is the full form, written as one word, used in formal writing such as essays, reports, or business letters. Both are correct.
How do you ask for permission with can?
Start the question with Can I or Can we, then add the action you want to do:
- Can I sit here?
- Can we leave early?
The answer is usually Yes, you can or No, you can't. Could is a more polite alternative (Could I sit here?), which you will learn at A2 level.
Is can a verb?
Yes, but it is a special kind of verb called a modal verb. Modal verbs are different from normal verbs: they have only one form for every subject, they don't use do/does, and they are followed directly by another verb in its base form. Other modals include could, will, would, must, may, might, and should.
Quick summary
- Can has three uses: ability (I can swim), possibility (It can rain here), and permission (Can I leave?).
- The form never changes — no -s, no to, no -ing.
- For negatives and questions, can moves by itself. Don't add do or does.
- Can't = cannot. Both are correct; cannot is one word.
- Short answers: Yes, I can. / No, I can't. — don't repeat the main verb.
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