Use can and can’t to say whether someone has the ability to do something now or in general. The structure is economical: the form does not change with the subject, and the next verb stays in its base form.
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The basic pattern
| Type | Pattern | Example |
|---|---|---|
| Affirmative | subject + can + base verb | Leah can swim. |
| Negative | subject + cannot or can’t + base verb | I can’t hear you. |
| Question | can + subject + base verb? | Can they join us? |
| Short answer | yes, subject + can | Yes, they can. |
Do not add to or an -s ending after can. Say “She can drive,” not “She can to drive” or “She cans drive.”
General and immediate ability
“I can read music” describes a learned ability. “I can see the station from here” describes what is possible in the present situation. Context tells us whether the ability is permanent or temporary.
A: Can you use this design program?
B: I can edit an existing file, but I can’t build a complex animation yet.
The answer is more informative than a simple yes or no because it defines the limit of the speaker’s ability.
Past ability
Use could for a general ability in the past: “My grandfather could speak three languages.” For one successful action in a particular difficult situation, was able to or managed to is often clearer: “Although the door was stuck, we were able to open it.”
In negatives, couldn’t works for both general and specific inability: “I couldn’t swim at five” and “I couldn’t open the file yesterday.”
Future and other verb forms
English does not use a normal future form of can. Use will be able to: “After the update, users will be able to export the report.” Use been able to after have: “I haven’t been able to contact her.”
Be able to is not always a perfect replacement. In everyday present-tense statements, “I can meet at four” is usually more natural than “I am able to meet at four.” The longer form can emphasize overcoming a limitation.
Ability, permission and possibility
The same modal can express different meanings. “Can you lift this box?” asks about ability. “Can I leave early?” requests permission. “It can get cold here at night” describes a general possibility. Decide which meaning is active before interpreting the sentence.
For a polite request, “Could you send the link?” is often softer than “Can you send the link?” Here, could does not refer to past ability.
Pronouncing can and can’t
In many affirmative sentences, can is unstressed and has a weak vowel: “I can COME.” The main verb carries the stress. Negative can’t is usually stressed: “I CAN’T come.” Exact pronunciation varies by accent, so listen for stress and context as well as the final consonant.
Practise pairs in complete sentences: “She can attend on Tuesday” and “She can’t attend on Tuesday.” Record both, then check whether the contrast remains clear when you speak naturally.
Common corrections
| Incorrect | Correct |
|---|---|
| He can plays chess. | He can play chess. |
| I don’t can log in. | I can’t log in. |
| Will you can come? | Will you be able to come? |
| She can to help. | She can help. |
Short practice
Complete these ideas with an appropriate form: “When I was ten, I ___ ride a bike.” “The network was down, but we ___ send the file from a phone.” “After the course, you ___ lead basic meetings.” Suitable answers are could, were able to, and will be able to.
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