May I 是征求意见的用法：
1、肯定回答：
1)Yes, you can/may.
2)Of course (you can).
3) Yes, please .
2、否定回答：
1) No, you can't / mustn't.
2)I'm afraid you can't.
3)You'd better not.
注：否定回答不能用 No, you may not .
3.含有情态动词的'一般疑问句的答语，例如：
Can I .... ?
Yes, you can.
No, you can't.