Casa ESL · grammar guides · level A1–A2
Can and Could — Ability, Permission, and Requests
Can is one of the hardest-working words in English: ability, permission, requests, and possibility, all in two or three letters. Could is its polite, past-tense shadow.
Ability: what you know how to do
Can + base verb, no -s ever, no to: "She can swim." / "I can't drive." Questions flip the order: "Can you cook?"
Could is the past: "I could read at four." For a single past achievement, English prefers was able to or managed to: "The fire spread fast, but everyone was able to escape."
Permission and requests
"Can I open the window?" asks permission; "Could I…?" asks more politely; "May I…?" is the formal classic. For requests aimed at others: "Can you help me?" → "Could you possibly help me?" climbs the politeness ladder.
The future problem: will be able to
Can has no future form — "will can" does not exist. Use will be able to: "After this course, you'll be able to hold a conversation." Same for the perfect: "I haven't been able to sleep."
| Meaning | Example |
|---|---|
| Present ability | He can juggle. |
| Past ability (general) | She could run fast as a kid. |
| Permission | Can I leave early? / Could I ask something? |
| Request | Could you pass the salt? |
| Future ability | You'll be able to see the results tomorrow. |
Common mistakes
✓ She can swim.
Modals never take -s.
✓ I can help you.
No to after can.
✓ I'll be able to come tomorrow.
Can has no future; use be able to.
Practice
- ___ you play chess when you were seven?
show answer
Could - Sorry, I ___ (not/come) to the meeting tomorrow.
show answer
can't come - After the surgery he ___ walk again. (future)
show answer
will be able to
FAQ
What is the difference between can and could?
Can expresses present ability, permission, and requests. Could is the past of can for general ability, and the more polite form for requests and permission.
Why is "will can" wrong?
Two modal verbs cannot combine in English. For future ability use will be able to: I will be able to attend.
Is "Can I…?" rude?
No — it is normal and friendly. Could I…? and May I…? are simply more polite or formal versions of the same request.
Want this to actually stick?
One-on-one lessons with a real teacher, or free worksheets for this level — your pace, your goals.
More guides: Present Simple · Past Simple · Present Continuous · Present Perfect