2013高考英语语法最后30天精讲精练

情 态 动 词

1、情态动词 + have done sth

这个结构有着特殊意义：用来表示猜测（设想可能发生过什么事情）或

想象（设想可能出现过什么不同的情况）

①should (ought to) have done sth 本来该做而未做

This wall oughtn’t to have been painted blue.

②need have done sth 本来有必要做而未做

You needn’t have told her the news.

③must have done sth 对过去所做动作的肯定推测

---We went to Paris. ---That must have been nice.

④can have done sth 对过去所做动作的否定或疑问推测

I don’t think he can have heard you. Call again.

Where can John have put the matches?

⑤may (might) have done sth 过去可能发生某事，与could相比，may和

might可能性较小，might 可能性更小；might 也可表示过去可能发生

而未发生的事情。

Polly’s very late----she may (might) have missed her etrain.

You were stupid to try climbing there. You might have killed youself

⑥could have done sth

●推测过去”可能“发生某事 （同can, 但can不用肯定句）

She could have gone off with some friends.

●表示过去没有实现的可能性：某事可能发生，但却没有发生

You were stupid to go skiing there----you could have broken