Grammar › Modal Verbs › Permission: Can, Could & May
Permission: Can, Could & May
Can, could and may all handle permission, at different levels of formality:
- Ask — Can/Could/May I…? (can = informal, may = formal).
- Give — You can / You may (not 'could').
- Refuse — You can't / You may not.
'Could' asks politely but isn't used to give permission: 'Could I…?' → 'Yes, you can.' (not 'you could').
Asking, giving and refusing permission
| Function | Words | Example |
|---|---|---|
| Ask (informal) | Can I…? | Can I sit here? |
| Ask (polite) | Could I…? | Could I borrow your pen? |
| Ask (formal) | May I…? | May I come in? |
| Give | You can / You may | You can go now. You may begin. |
| Refuse | You can’t / You may not | You can’t park here. |
When to use each
1. Ask — choose the formality
- Can I have some water? (informal)
- Could I ask a question? (polite)
- May I leave the table? (formal)
2. Give permission — can / may
- Yes, you can borrow it. Students may use the library after 6.
3. Refuse — can’t / may not
- Sorry, you can’t go in there. Passengers may not smoke.
⚠️ Answer ‘Could I…?’ with can, not could: “Could I leave early?” — “Yes, you can.” (not
you could).
Common mistakes
1. Giving permission with ‘could’. Yes, you could → Yes, you can.
2. Adding ‘to’. Can I to go? → Can I go?
3. Over-formal ‘may’ in casual speech. May I have a coffee? in a café with friends → Can I have a coffee? is more natural. Pro tip: can = informal, could = polite ask, may = formal; give/refuse with can/may (not could).
✏️ Practice: Permission: Can, Could & May
1. ___ I sit here? (informal)
2. ___ I come in? (formal, at an office)
3. 'Could I borrow your charger?' — 'Yes, you ___ .'
4. Sorry, you ___ park here — it's for staff only.
5. ___ I ask you a question, please? (polite)
6. Students ___ use the lab after 6 p.m. (giving permission, formal)
7. Passengers ___ smoke anywhere on the train.
8. Correct this: 'Can I to leave early today?'
9. 'May I take your coat?' is an example of…
10. Which is used to ASK but not to GIVE permission?
Frequently asked questions
What's the difference between can, could and may for permission?
They differ in formality: 'can' is everyday, 'could' is a bit more polite for asking, and 'may' is formal. All ask for permission; 'can' and 'may' also give it.
Why can't I give permission with 'could'?
'Could' is used to ask politely, but the answer uses 'can' or 'may': 'Could I leave early?' — 'Yes, you can.' 'You could' would sound like advice, not permission.
How do I refuse permission?
Use 'can't' or 'may not': You can't smoke here; Visitors may not use this door. 'Mustn't' also works for strong prohibition.
Is 'may' too formal for everyday use?
In casual speech, 'can' is normal (Can I have a menu?). 'May' fits formal or polite service contexts (May I take your coat?).
👩🏫 For teachers
CEFR objectives for “Permission: Can, Could & May”:
- Can ask permission with can/could/may at the right level of formality (CEFR A2).
- Can give and refuse permission with can/may and can't/may not.
- Can avoid giving permission with 'could'.
⬇︎ Download the Lesson Pack (PDF)
Printable worksheet + answer key + one-page summary. Free to use and print in class with attribution. Join the newsletter for new packs and cheat sheets.