Can
The use of can to ask or grant permission has been common since the 19th century and is well established, although some commentators feel may is more appropriate in formal contexts. May is relatively rare in negative constructions (mayn't is not common); cannot and can't are usual in such contexts. These words are used to talk about ability, awareness, and possibility. They are also used to say that someone has permission to do something. 
Can
Can is usually used in standard spoken English when asking for permission. It is acceptable in most forms of written English, although in very formal writing, such as official instructions, may is often used instead: Persons under 14 unaccompanied by an adult may not enter. Green fingers and thumbs The language of gardening. Add can to one of your lists below, or create a new one.
CAN
To describe a specific occurrence in the past, use was/were able to instead of could. To access it, add this site to the exceptions or modify your security settings, then refresh this page. It is used with the base form of a verb. 
CAN definition in American English
You use can to indicate that someone has the ability or opportunity to do something. Don't worry yourself about me, I can take care of myself. I can't give you details because I don't actually have any details. The United States will do whatever it can to help Greece. Definition of can 1 modal verb from the Oxford Advanced Learner's Dictionary. Toggle navigation.
Can
used to say that it is possible for somebody/something to do something, or for something to happen. I can run fast. Can you call back tomorrow? He couldn't answer the question. The stadium can be emptied in four minutes. I can't promise anything, but I'll do what I can. Please let us know if you cannot attend the meeting. Can and may are most frequently interchangeable in uses denoting possibility; because the possibility of one's doing something may depend on another's acquiescence, they have also become interchangeable in the sense denoting permission. The use of can to ask or grant permission has been common since the 19th century and is well established, although some commentators feel may is more appropriate in formal contexts. CAN Definition & Meaning
Define can. can synonyms, can pronunciation, can translation, English dictionary definition of can. to be able to, have the power or skill to: I can take a bus to the airport. . 
Can
Despite the insistence by some, that can means only "to be able'' and may means "to be permitted,'' both are regularly used in seeking or granting permission: Can (or May) I borrow your tape recorder?. .
Can Definition & Meaning
The present tense negative can not is usually contracted to cannot (more formal) or can’t (less formal). The use of can in asking permission is sometimes criticized as being impolite or incorrect by those who favour the more formal alternative “may I?”. .