Aren't "can" and "may" interchangeable when requesting permission ?

Answer 1

Can means is it possible, may is a request

Answer 2

Can, Usage:
Generations of grammarians and schoolteachers have insisted that can should be used only to express the capacity to do something, while may must be used to indicate permission. Technically, correct usage therefore requires: The boss said that anyone who wants an extra day off may (not can) have one. May (not can) I have an extra blanket? In spech, however, can is used to express permission by most speakers, and the "permission" use of can is even more frequent in British English. The negative contraction Can't I have the car tonight? Many members of the Usage Panel feel also that the alternative contraction mayn't is awkward and unnatural.
-The American Heritage Dictionary Second College Edition
from the usage of can

Answer 3

No, they are not. "Can" indicates ability - things you have the ability to do, that you are able to do. For example, "Can I drive the car?" - would be answered, "Certainly, if you have your license and are a good driver, go ahead." "May" is asking the question for permission to do something. For example, "May I drive the car?" - could be answered "Yes, you have my permission to drive", or "No, I will never let you drive the car". People use the two terms interchangeably when they definitely are not.

Answer 4

Can indicates an ability. May asks permission. They are not interchangeable.

Answer 5

Originally, no they weren't. "can" was more in the realm of "am i capable of this" and "may" meant "do I have permission to do this". In modern language usage, however, they have become interchangable, probably because in modern society there is less emphasis placed on etiquette and fewer societal restrictions.

Answer 6

Can and may are interchangeable according to my high school english teacher. Many of my teachers in the past would "trick" us when we said "Can I go to the bathroom?" and they would respond by saying, "I don't know can you?" But they are indeed interchangeable.

Answer 7

Formally they are not. Only "may" is supposed to be used for permission. But with increased usage of "can" for permission, it is pretty much acceptable.

Answer 8

Technically, "can" implies the ability to do something, whereas "may" implies permission.
However, most people will use them interchangeably, but you'll occasionally find the one person who will ridicule you for not knowing the difference:

"Can I go to the bathroom?"
"I don't know. Can you?" (Translation: "Are you able to go to the bathroom?"

Answer 9

In normal conversation, they tend to be used interchangeably, but technically they aren't. "Can" refers to ability - do I have the strength, skill, etc. to do whatever. "May" refers to permission - will i be allowed to do whatever.

Answer 10

no - can asks if it is possible to do it at any point in time - may asks permission to do it now

examples -

Can i dance on the teacher desk?
yes, it is physically possible to dance on the teachers desk

May i dance on the teachers desk?
No, you may not - you could fall and get huirt or break something - we are in the middle of a lesson - any number of reasons why you may not.

Can i go to the bathroom?
yes physically you can nothing is physically stopping you

May i go to the bathroom?
when you finish the test you may go - after the lecture you may go - yes you may go

Answer 11

Not strictly, though they often are used so. "Can I" indicates that one is asking about ability. "May I" is an actual request for permission.