情态动词+have+done
I.对过去的推测
一、 “must+have+done”表示对过去事情的肯定推测，译成“一定做过某事”，只用于肯定句。 1. It must have rained last night, for the ground is wet. 昨晚一定下雨了，因为地面还是湿的。 2. You must have been mad to speak to the servant. 你和仆人说话，一定是发疯了。
二、 “can't+have+done”表示对过去事情的否定推测，译成“不可能做过某事”， 只用于否定句。 1. Mr. Smith can't have gone to Beijing, for I saw him in the library just now. 史密斯先生不可能去北京了，我刚才还在图书馆见过他。 2. Mary can't have stolen your money. She has gone home.
玛丽不可能偷你的钱，她回家去了。
三、 “can+have+done”表示对过去行为的怀疑，用于疑问句，译成“可能做过……吗？”。 1. There is no light in the room. Can they have gone out? 屋里没有灯，他们可能出去了吗？
2. There is nowhere to find them. Where can they have gone?
到处找不到他们，他们可能到什么地方去呢？
四、“may+have+done”表示对发生过的事情的推测，是“可能已经”或“也许已经”，用于肯定句中。 —What has happened to George? —I don't know. He may have got lost.
—乔治发生了什么事？ —我不知道，他可能迷路了。
五、 “might+have+done”表示对过去事情的推测，might与may意思相同，但可能性更小。 1. He might have given you more help, even though he was busy. 他或许会多给你一些帮助，即使他很忙。
2. She might have achieved greater progress, if you had given her more chances.
如果你多给她点机会，她可能已经取得更大的成绩。
II.对过去事实进行相反的假设
六、 “could+have+done”是虚拟语气，表示对过去事情的假设，意思是本来能够做某事而没有做。 He could have passed the exam, but he was too careless. 本来他能够通过考试，但是他太粗心。 七、 “would+have+done”虚拟语气，表示对过去事情的假设，意思是“本来会做而没有做”。 1. I would have told you all about the boy's story, but you didn't ask me. 我本来会告诉你这个小男孩的故事，但是你没有问我。 2. Without your help, I wouldn't have achieved so much. 没有你的帮助，我是不会取得如此大的成绩。
八、 “should+have+done” 意思是“本来应该做某事，而实际没做。”
“shouldn't+have+done” 表示本来不应该做某事，而实际做了。含有指责对方或自责的含意。 1. Tom, you are too lazy. The work should have been finished yesterday. 汤姆，你太懒惰了，这项工作本来应该昨天就做完的。 2. Look, Tom is crying. I shouldn't have been so harsh on him. 看，汤姆哭了，我本来不应该对他如此严厉。
九、 “ought (not) to+have+done”与“should (not)+have+done”用法基本一样。 I ought to have gone home last Sunday. 我理应上星期日回家。
You ought not to have given him more help. 你不应该帮助他那么多。 十、 “needn't+have+done”则表示“本来不必要做某事而做了”。
I needn't have bought so much wine—only five people came. 我本来没有必要买这么多酒，只来了五个人。
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巩固性练习：
1．---You didn’t wait for Mr. Smith last night, did you? ---No, but we ______. He didn’t return home at all. A. couldn’t have waited B. needn’t have C. didn’t need to D. should wait 2．Harry ______ have won the Physics competition easily yesterday, but he gave up. A. could B. might C. should D. must
3．---May I speak to your manager Mr. Smith at six o’clock tonight ?” ---“I’m sorry, Mr. Smith to a conference before then.”
A. will have gone B. had gone C. would have gone D. has gone 4．---Tom took away our teacher’s cell phone without being permitted. --- Really? I can’t imagine that he _______ have done such a thing. A. must B. may C. can D. should
5．--- Was it you that made the suggestion? --- It _______ have been. I can’t remember. A. need B. must C. should D. may
6．The weather turned out to be fine yesterday. I_________ the trouble to carry my umbrella with me . A. should have taken B. could have taken C. needn't have taken D. mustn't have taken 7．He paid for a seat, when he ______ have entered free.
A. could B. would C. must D. need
8．I didn’t see her in the meeting room this morning. She ________ at the meeting . A. mustn’t have spoken B. mightn’t have spoken C. can’t have spoken D. shouldn’t have spoken
9．--- Hi, is that Peter Brown? ---Sorry. You ______ the wrong number .
A. must dial B. must have dialed C. should dial D. should have dialed
10．I was on the highway when this car went past followed by a police car . They ______ at least 150 kilometers an hour .
A. should have been doing B. must have been doing C. could have done D. would have done
Key 1---5 CAADD 6---10 CACBB
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