Can indicates an ability to do something. I can = I am able toCan表示做某事的能力。我能……
"May" has the meaning of "might" (you may or you may not)“May”的意思是“可能”(你可能，也可能不是)I may go to the movies tonight. (There is a possibility that I may; but, I might not.)我今晚可能去看电影。(我有可能会;但是，我可能不会。)I can go to the movies tonight. (There's nothing to interfere with my ability to go. I don't have other plans or I have transportation. I can go.)我今晚可以去看电影。（没有什么能妨碍我去。我没有其他计划，或我有交通工具。我可以去)。
However, "can" and "may" are often used interchangeably interrogatively:然而，“can”和“may”通常可以交换，在疑问句中使用:"May I have a glass of water?" and "Can I have a glass of water?" both mean the same thing. "May" is considered a more polite way of asking for something, but "can" is used in casual speech with the same meaning as "may."“May I have a glass of water?”和“Can I have a glass of water?”都是同一个意思。“May”被认为是请求某事的一种更礼貌的方式，但“can”在非正式的讲话中与“May”的意思相同。,
