情态动词加havedone虚拟语气（情态动词havedone可以有哪些用法用途）

情态动词＋have done，接下来我们就来聊聊关于情态动词加havedone虚拟语气?以下内容大家不妨参考一二希望能帮到您!

情态动词加havedone虚拟语气

情态动词＋have done

1.表对过去的推测：

(1) must have done：意思是“一定已经”。

If he had really been there，I must have seen him. 如果他当时确实在那里，我一定会看见他。

Her watch must have stopped. I will go and call her. 她的表准是停了。我去叫她。

(2)may/might have done：

可用于肯定句(“可能已经”)和否定句(“可能没有”)；might的语气没有may那么肯定。

She may have read the book. 她可能已经看过这本书了。

He might not have got your letter. 他或许没有收到你的来信。

(3)can/could have done: can常用于否定句(“不可能已经”)和疑问句；

Don’t worry—they would have just forgotten to phone. 别担心——他们很可能只是忘了打电话。

Where can he have gone? 他可能去哪里了呢？

2.表虚拟。

(1) needn't have done: “根本不必；本来不必”，也可用于疑问句

You needn’t have told them that.你没有必要告诉他们那个。

Need they have done it last week? 他们上周做这事有必要吗？

(2) should/ought to have done：肯定式表示“过去本应做某事(但没做)”；否定式表示“过去不该做某事(但做了)”。该句式含有不满或责备之意。

You’ re right. I should have thought of that. 你说得对，我应当想到那点(但没想到)。

She ought to have been more careful. 她本该更小心些。

(3) would have done：表示过去本来要做某事却因某种原因未做，通常用来说明某种情况，但不像用should或ought to那样含有责备之意。

I _would _have _written_ to you earlier，but I have been ill. 我本来要早点给你写信，但我生病了。

If I had seen the advertisement，I would have got the job.

我要是看见那个广告了，我就申请那份工作了。

(4) could have done :表示本来能够做，实际上未做某事，用于肯定句。

He could have helped you, but he was not free yesterday.

(5) might have done: 表示本来可能做，实际上未做某事，用于肯定句和否定句。

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