What Can and Can't Are
Can says that something is possible: you have the skill, or the situation allows it. Can't says the opposite. The comfortable part is that can never changes its form, and the verb after it goes back to being plain.
ABLE TOA skill you have
Every subject uses the same word can — not one of them adds -s.
She can swim very well.
Cô ấy bơi rất giỏi.
NOT ABLE TOA skill you do not have
He can't drive a car.
Anh ấy không biết lái ô tô.
That is the single most useful fact in this lesson. He cans swim and He can swims are both impossible, and so is He can to swim — the verb after can is always bare, with no -s and no to. Vietnamese helps here: có thể has one form for every person too.
TRY IT
- Question 1
"He swim."
- Question 2
"She can the piano."
The four shapes
AFFIRMATIVE
ScanV
He can play the guitar.
One form for I, you, he, she, it, we and they.
NEGATIVE
Scan'tV
He can't play the piano.
Can't is the everyday form; cannot is the full one.
QUESTION
CanSV?
Can you play chess?
Can moves to the front by itself. Do is never used.
SHORT ANSWER
Yes / No,Scan / can't
Yes, I can. — No, I can't.
Repeat can, not the main verb.
WRITING THE NEGATIVE
- can + notcannot
- cannotcan't
cannot is one solid word · can't takes the apostrophe and does most of the work
Written down the two are easy to tell apart; heard, they are not. In a positive sentence can is almost swallowed — I can swim comes out closer to I c'n swim, with the stress on swim. In the negative the opposite happens: can't takes the stress and is said in full — I CAN'T swim. The final t often disappears in fast speech, so what separates the two sentences is the stress, not the letter. If you are not sure what somebody said, ask: Sorry — can you, or can't you?
TRY IT
- Question 1
"I'm sorry, I come to your party."
- Question 2
" you help me with this box?"
- Question 3
"Can your brother drive? — "
When to use it
Ability
I can drive, but I don't have a car.
Something you know how to do.
Signal words: swim · cook · drive · speak English
Permission
Can I sit here?
Asking whether you are allowed to do something.
Signal words: Can I …? · You can …
A request
Can you pass me the salt?
Asking somebody else to do something for you.
Signal words: Can you …? · Could you …?
What the situation allows
You can pay by card here.
Something the place permits, not a personal skill.
Signal words: You can … · We can … · It can …
The last card is worth a second look. You can pay by card here says nothing about your abilities — it describes what the shop allows. English uses one word for both ideas, and the situation tells you which is meant.
Can I…? vs. Can you…?
Two questions that look identical and differ by one word — and the difference is who does the work. Mixing them up leaves you with a polite, grammatical sentence that means the wrong thing, which is harder to spot than a grammar mistake.
| CAN I…? | CAN YOU…? | |
|---|---|---|
| Example | Can I use your phone? | Can you call me later? |
| Who acts | The speaker — you. | The listener. |
| What it does | Asks permission. | Makes a request. |
| More polite | Could I …? | Could you …? |
| Usual replies | Yes, of course. · Sure, go ahead. | Yes, of course. · Sorry, I can't. |
Both soften with could and with please: Could you call me later, please? At A1 treat could here as simply a more polite can — it is not a past tense in this use, and the imperatives lesson uses it again.
TRY IT
- Question 1
You have no pen. " borrow your pen, please?"
- Question 2
The room is too hot. " open the window, please?"
Common mistakes
Incorrect:He cans swim.
Correct:He can swim.
Can has one form for every subject and never takes the third-person -s.
Incorrect:She can to drive a car.
Correct:She can drive a car.
The verb after can is bare: no to, ever.
Incorrect:Do you can swim?
Correct:Can you swim?
Can is an auxiliary itself, so it forms its own question and never borrows do.
Incorrect:He can plays the piano.
Correct:He can play the piano.
Can has already told you the subject; the main verb goes back to its base form.
Incorrect:Can you cook? — Yes, I cook.
Correct:Can you cook? — Yes, I can.
A short answer repeats the auxiliary of the question, not the main verb.
Incorrect:He can't to come tomorrow.
Correct:He can't come tomorrow.
The negative changes nothing after it — the verb stays bare in can't sentences too.
Quick check · 6 questions
Choose the correct sentence:
My grandmother can cook very well.
- A. can cook — Correct
- B. can cooks
- C. cans cook
Answer: A. can cook
Can has one form for every subject, and because it has already taken the grammatical weight the verb after it stays bare.
Choose the correct negative:
I can't swim.
- A. can't — Correct
- B. am not can
- C. don't can
Answer: A. can't
Can borrows neither do nor be. The n't attaches straight to can itself.
Choose the word that starts the question:
Can your sister speak English?
- A. Can — Correct
- B. Does
- C. Is
Answer: A. Can
Can is already an auxiliary, so adding does would give the sentence two of them.
Choose the correct short answer:
"Can you drive?" — "No, I can't."
- A. can't — Correct
- B. don't
- C. can't drive not
Answer: A. can't
A question that opens with Can closes with can or can't, and the main verb drops out entirely.
You want the other person to open the door. Choose the right question:
Can you open the door, please?
- A. Can you — Correct
- B. Can I
Answer: A. Can you
Can I…? asks permission for yourself; Can you…? asks somebody else to act. Mixing them up still leaves you with a polite, grammatical sentence, which is why the mistake is so hard to catch.
Choose the correct sentence:
I can speak Japanese.
- A. can speak — Correct
- B. can
- C. speak can
Answer: A. can speak
Can never stands as the main verb of a sentence. It has to say what you are able to do: can speak, can read, can write.
See whether it really stuck.
Start the quiz · 12 questions
