When asking a question, what's the difference between using "can" and "may"?

Question

Example - May / Can I borrow your book?

Answer 1

Can I borrow your book?

The above question, using "can," could technically be understood as, "Am I [physically] ABLE to borrow your book?" An example of a response to that question could be, "Yes, you are [physically] ABLE to borrow my book, but I won't allow you to."

May I borrow your book?

This question, using the word "may," is asking for permission. It could be understood as asking, "Do I have permission to borrow your book?" An example of a response to this question could be, "No, I will not permit you to borrow my book because I do not trust you with my belongings."

Hope this helps and that you understand the difference! ;-)

---

In response to the poster above me, there is always the formal/informal side to this.

If you consider "may" and "can" to have the same meaning of just asking for permission, then yes, "may" is considered formal, and "can" is considered "informal." This, however, is not the only difference between the two words, as I demonstrated above.

Once again, hope this helps! ;-)

Answer 2

Can means 'able to'. May is asking permission. So the correct question would be May I borrow your book?

Answer 3

can refers to your ability to do something. are you able to borrow the book or would you fail at borrowing?

may is a permission thing.

examples
Q: can i borrow your book? A: yes, if you try really hard.
Q: may i borrow your book? A: sure, i don't mind.

Answer 4

can= a physical ability
may= is it permitted or allowed

Can I borrow a book?= Do I have the physical ability to borrow the book?

May I borrow the book?= Do I have your permission to borrow the book?

Answer 5

Can, although commonly used among people is the incorrect (ethically speaking) way of asking for something. Well, most of the time. Can means you are physically able to attain the book and borrow it. For instance, I ask my mother, "Can I eat that hamburger?" she would ask me back, "I don't know, can you?" implying that she thought I asked her if I was impaired or something.

Usually may is asking for permission. "May I be excused", "May I help you", "May I eat that hamburger?". It's more or less a polite way of asking for something, rather than asking if you can physically do it.

Answer 6

Hi :) Great question! :)

Here's something that I teach my students all the time to distinguish the difference. I hope it can help you :)

<<"May I" shows that the speaker accepts or understands that the listener has direct authority to grant permission. "Can I" shows that the speaker accepts or understands that the listener has indirect authority to grant permission or has knowledge of the rules/prohibitions.

May I smoke in here?

OK, go on, I'll let you.
-------------------------------------------------------
Can I smoke in here?

Yes, I think so.

Answer 7

there is no difference as long as people understand what you mean.

Answer 8

"Can" is like a way of asking someone for something. "May" is like...more respectful.