二、句型剖析

　　1.may/might have done 或许做过某事

　　【典型例句】

　　She might not be annoyed because she is usually very patient.

　　她可能不会烦躁,因为她通常很有耐心。

　　He may have gone back home,because he didn't say he would take part in her birthday party.

　　他可能已经回家了,因为他并没有说会参加她的生日聚会。

　　Most of the miners might have died but for the immediate rescue.

　　要不是及时的援救,大部分煤工可能死去。

　　【要点归纳】

　　may/might have done用来对过去的情况进行猜测。如果对现在或将来的情况进行猜测,要用"may/might+do"或may/might be doing。might表示的可能性更小。might have done还可表示与过去事实相反的猜测。

　　【相关链接】

　　(1)"could+have done"表示"本来能够做某事",也可表示对过去情况的猜测。如:

　　He couldn't have been angry then.他当时不可能生气。

　　(2)can't/couldn't+have done表示"不可能发生某事"。如:

He thought his son couldn't have taken all the tablets.他认为他儿子不可能把药全都吃了。