Grammar choices
Can vs. May
Can is about ability or possibility: I can swim. May is about permission or possibility: You may leave early. In casual speech, can is widely used for permission too, but may is more polite and formal.
| Word | Part of speech | Meaning |
|---|---|---|
| can | verb | to be able to do something, or to know how to do it |
| verb | to be allowed to; used informally to ask for or give permission | |
| may | verb | to be allowed to; used to ask for or give permission politely |
| verb | used to say that something is possible |
Can
verb: to be able to do something, or to know how to do it
- Ana can type faster than anyone in the office.
- Can you hear me in the back of the room?
verb: to be allowed to; used informally to ask for or give permission
- You can borrow my car if you fill up the tank.
- Can I sit here, or is this seat taken?
May
verb: to be allowed to; used to ask for or give permission politely
- May I ask a question about the homework?
- Guests may use the pool until ten at night.
verb: used to say that something is possible
- It may rain later, so bring a jacket.
- The store may be closed on the holiday.
How to remember the difference
Can goes with capable: what you are able to do. May goes with the children's game Mother May I, about what you are allowed to do.
Good to know
Using can for permission is standard in everyday English, and dictionaries accept it. The old rule still matters in formal requests and polite service, where May I help you? sounds better. For possibility, may and might are both fine; might sounds a little less likely.
Spot the mistake
Dear Dr. Moreno,
canmay I request an extension on my final paper?Correct: Dear Dr. Moreno, may I request an extension on my final paper?
My little brother
maycan already read chapter books at age five.Correct: My little brother can already read chapter books at age five.
Check yourself
Pick the word that fits each sentence.
1. Our new puppy already sit and shake hands.
Answer: can. The sentence is about what the puppy is able to do, so it is can.
2. Excuse me, sir, I take this chair?
Answer: may. This is a polite request for permission, so may is the formal choice.
Strunk wrote about this in 1918: his note on can in The Elements of Style.