The words 'may 'and 'can' are both auxiliary verbs. People are often confused about which word to use because of their similar meanings. This paper looks at the definitions of the two verbs and explains why they are commonly misused.
             The definitions of the word 'may' include (http://www.answers.com/may):
             1.To be allowed or permitted to: May I take a swim? Yes, you may.
             2.Used to indicate a certain measure of likelihood or possibility: It may rain this afternoon.
             3.Used to express a desire or fervent wish: Long may he live!
             4.Used to express contingency, purpose, or result in clauses introduced by that or so that: expressing ideas so that the average person may understand.
             The definitions of the word 'can' include (http://www.answers.com/can):
             a.Used to indicate physical or mental ability: I can carry both suitcases. Can you remember the war?
             b.Used to indicate possession of a specified power, right, or privilege: The President can veto congressional bills.
             c.Used to indicate possession of a specified capability or skill: I can tune the harpsichord as well as play it.
             a.Used to indicate possibility or probability: I wonder if my long lost neighbor can still be alive. Such things can and do happen.
             b.Used to indicate that which is permitted, as by conscience or feelings: One can hardly blame you for being upset.
             c.Used to indicate probability or possibility under the specified circumstances: They can hardly have intended to do that.
             The major cause of misuse comes from the fact that 'can' means "to be able to" while 'may' means "to be permitted to" ("Dr. Grammar – Frequently Asked Questions"). These definitions are similar and the following example should help understand the difference. A correct use of 'can' is "Can you come to school today?", meaning the same as "Are yo...