Virtuous English Academy
Can and Can't: Ability in English (A1)
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The modal verb can expresses ability and possibility, while can't expresses the lack of it. This lesson pairs can and can't with common action verbs so you can say what you are and are not able to do.
Can is a modal verb, and it is the first one most learners meet. It expresses three things that come up constantly in everyday English: ability, possibility and permission. I can swim describes a skill, We can meet on Friday describes a possibility, and You can use my laptop grants permission — one small word covering three large jobs.
Modal verbs behave differently from ordinary verbs, and once you learn their pattern you get several verbs for the price of one. Can never takes an -s in the third person, never uses do or does in questions and negatives, and is always followed by the bare infinitive with no to. He can swim, not He cans swim or He can to swim.
The negative is can not, but it is almost always written as one word, cannot, or contracted to can't. Of the three, can't dominates speech and informal writing, cannot belongs in formal writing, and the separated can not is rare and usually only appears for emphasis.
How to form Can and Can't: Ability
| Form | Structure | Example |
|---|---|---|
| Affirmative | subject + can + base verb | She can drive. |
| Negative | subject + can't/cannot + base verb | She can't drive. |
| Question | can + subject + base verb | Can she drive? |
| Short answer (yes) | Yes, + subject + can | Yes, she can. |
| Short answer (no) | No, + subject + can't | No, she can't. |
| Past ability | could / couldn't + base verb | She could drive at seventeen. |
Can and Can't: Ability: the key rules
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Can + base verb expresses ability, and the form never changes — no -s for he/she/it.
She can swim. They can cook.
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The negative is cannot, almost always shortened to can't.
I can't drive, but I can ride a bike.
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Make questions by inversion: Can + subject + verb?
Can you speak French? — Yes, I can. / No, I can't.
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Can also asks permission and makes informal requests.
Can I open the window? Can you help me, please?
When to use Can and Can't: Ability
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Talking about skills and abilities
The most common use at A1 — what you have learned to do, and what you have not.
I can speak three languages, but I can't play any instruments.
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Asking for and giving permission
Can is the everyday way to ask whether something is allowed, and to say yes or no.
Can I open the window? — Yes, of course you can.
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Making requests and offers
Can you asks someone to do something; can I offers to do something for them.
Can you help me with this? — Can I carry that for you?
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Saying what is possible or available
Can often describes general possibility rather than personal ability.
You can buy tickets online. It can get very cold in January.
can vs. could for politeness
Both forms are correct in requests, but they carry a different level of formality. Choosing the right one is a matter of social register rather than time.
can — direct and friendly
Normal with friends, family and colleagues you know well. Neutral rather than rude.
Can you pass me the salt? Can I borrow your pen?
could — softer and more polite
Better with strangers, in shops and offices, or when asking a bigger favour. Here could is not a past tense.
Could you tell me the way to the station? Could I have the bill, please?
Can and Can't: Ability in example sentences
- My daughter can read already.Ability — no -s on can even with she.
- I can't come to the meeting tomorrow.can't + base verb; the contraction dominates in speech.
- Can you hear me at the back?Question formed by inverting can and the subject — no do.
- You cannot park here between nine and six.cannot in formal written English, typical of signs and notices.
- Can I pay by card?Asking permission in a shop.
- We can meet on Thursday if that suits you.Possibility rather than ability.
- She could swim when she was four.could as the past form of can for general past ability.
- Yes, I can. — No, I can't.Short answers repeat can and never add the main verb.
Can and Can't: Ability in a real conversation
Three different meanings of can appear here — ability, permission and request. See if you can label each one.
Manager:Can you use spreadsheet software?
Applicant:Yes, I can. I can also build simple databases.
Manager:Good. Can you start on Monday?
Applicant:I can't start until the tenth, I'm afraid.
Manager:That's fine. Could you send me your certificates before then?
Applicant:Of course. Can I email them tonight?
Common mistakes (and how to fix them)
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He cans play the guitar.
He can play the guitar.
Modal verbs like can never take -s.
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I can to swim.
I can swim.
After can use the base verb without to.
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Do you can help me?
Can you help me?
Can makes its own questions by inversion — never combine it with do.
Practice questions
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She ___ speak three languages. She is very talented.cancanscan to
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An elephant ___ climb tall trees. It is too heavy.cancan'tcans
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___ you swim across the big pool?CanDoIs
Practise Can and Can't: Ability today
Because can never changes form, practice should focus on the surrounding structure rather than the verb itself.
- Write five things you can do well and five things you can't do at all.
- Turn these into questions: You can drive. — She can cook. — They can come early.
- Ask for permission in four situations: a shop, a classroom, a friend's house, an office.
- Rewrite four of your can requests as more polite could requests.
Can and Can't: Ability: frequently asked questions
Should I write cannot or can not?
Write cannot as one word in almost every case — it is the standard form and the only one most style guides accept. The two-word can not appears occasionally for emphasis or when not belongs to a following structure, as in You can not only read it but also download it. In speech and informal writing, can't is by far the most common form and is entirely appropriate.
Why is there no -s in he can?
Can is a modal verb, and modal verbs never inflect. They take no -s in the third person, no -ing form and no infinitive with to. This applies to the whole family — can, could, will, would, shall, should, may, might, must. So He can swim is correct and He cans swim is not, in the same way that He must go is correct and He musts go is not.
What is the difference between can and be able to?
In the present they are nearly interchangeable, though can is far more common and sounds more natural: I can swim rather than I am able to swim. Be able to becomes necessary where can has no form of its own, particularly in the perfect and the future: I have been able to work from home, I will be able to help tomorrow. Be able to also sounds more formal, which occasionally suits written English.
How do I pronounce can and can't clearly?
In connected speech the positive can is usually weak and reduced to a very short sound, while can't is stressed and longer. This means the difference is carried mainly by stress and vowel length rather than by hearing the final t, which British speakers often drop. If a listener needs certainty, native speakers stress the whole phrase — I CAN come or I CANNOT come — and you can safely do the same.