高考英语二轮复习：“情态动词 完成时”的语法用法知识点总结（素材）

1、高中英语语法重难点 高考学习/复习微专题【高频考点精讲版全国通用】02“情态动词+完成时”的语法用法知识点总结课本中有这样一个句子：Frederick William I, the king of Prussia, could never have imagined that his greatest gift to the Russian people would have such an amazing history.普鲁士国王威廉一世绝不可能想到，他送给俄罗斯人民的厚礼会有这样一段令人惊讶的历史。句中could never have imagined表示什么含义呢？同学们可能会碰到这样

2、的问题：情态动词之后必须接动词原形吗？如果不是动词原形而是完成式，那么表达的意思是什么呢？所谓的“动词原形”，指的是跟在情态动词后面的那个动词要用原形。事实上，情态动词后面的动词，除了原形以外，可用进行式、完成式等。例如：She might be waiting for you.她可能在等你。You must have seen him.你一定见过他了。She may have missed her train.她可能误火车了。The door must have been locked by my wife.门一定是我妻子锁的。课本中，could have imagined即是“情态动词+完

3、成时”结构，在这里表示对过去情况的推测。注意，原句用的是否定形式，表示“过去不可能发生的情况”（could never have imagined意为“不可能想到”）。本文对情态动词后用完成时的情况，以及所表达的语法意义，做一点总结。一、must have done的用法must have done表示“对过去情况肯定的推测”。该结构只用于肯定句。意为“一定做过某事；肯定做了某事”。Rosa must have attended the party last night.罗莎昨天晚上一定参加了晚会。Angus must have read the book before.安格斯以前一定读过这本

4、书。It must have rained last night, for the road is all wet.昨晚一定下过雨，因为道路都是湿的。【注意】英语中不存在must not have done的说法，must have done的否定式是cant /couldnt have done二、may/might have done的用法1. may/might have done表示“对过去情况不肯定的推测”，might的语气比may弱。这种结构可以是肯定句，意为“可能做过某事”；也可以是否定句。意为“可能没有做过某事”。但不可以是疑问句，若表示疑问，则用Can/Could . hav

5、e done?She may have read it in the papers.她可能在报上已读到过此事。They may not have known it before hand.他们事先可能不知道这事儿。You might have known about it from Milla.你可能从米拉那儿了解了此事。He might have gone to have his hair cut.他可能理发去了。There might have been someone waiting outside.可能曾有人在外面等候。Ill try phoning him, but he may h

6、ave gone out by now.我要给他打电话，但他现在可能出去了。She may have missed her train.她可能误火车了。2.might have done表示未曾实现的可能性该结构仅限于使用might,不用may。表示过去本来可以发生，而实际上没有发生的情况，即“过去本来可以做某事，而实际没有做”。通常译为“本来可以”，“本来可能”等。例如：A lot of men died who might have been saved.很多人本来可以获救的却死了。He came home alone. You shouldnt have let him do that;

7、 he might have got lost.他独自回家了。你本不应当让他那么做的，他可能会迷路的。You were stupid to try climbing up there. You might have killed yourself.你从那儿往上爬，太蠢了，你可能会摔死的。You might have phoned to let us know where you were.你本来可以打个电话让我们知道你在哪。有时，也可根据语境译为“好在没有”，“差点”，尤其是当谈论的是不利情况时。如：It was really very dangerous. You might have in

8、jured him.真是很悬，你差点把他打伤了It was really very dangerous. I might have killed myself.那真的是太危险了，我差点没命了。3. might have done除了含有上述的意思外，还表示批评或责备即表示过去本来有责任或义务应该做某事的，但实际上却没有做成，含有批评和责备的意味，通常译为“本来应该”，“本来可以”等，用法同上。例如：You might have let me know before!你要是早点让我知道就好了!She might have told me she was going to stay out all

9、 night.她要是一夜不回来，应事先告诉我一声呀。You might have taken the trouble to tell me the meeting was put off.你本来可以费心告诉我一声会议推迟了的。You might have told us half an hour ago.你半个钟头前告诉我们就好了。4.might have done用于虚拟语气在虚拟条件句中，当谈论过去的情况时，其句型通常是：主句用“could/would/might +have+过去分词”，if从句用过去完成时。例如：We might have arrived earlier if we h

10、ad taken the other road.如果我们当时走了另一条路，就可能到得早一些。If you had left it there, someone might have stolen it.要是你当时把那东西落在那里，就可能有人把它偷走。If the weather hadnt been so bad, we might have gone out.如果天气不是那么坏，我们可能都出去了。I might have saved his life if I had found him earlier.要是我那时早点找到他的话，我可能会把他救活的。三、can/could have done

11、的用法1.can/could have done表示“对过去的可能性推测”，could的语气较can弱。该结构表推测时无肯定式，一般用于否定句和疑问句。否定句表示“过去不可能发生过某事”，它是must have done的否定式；疑问句表示“过去可能发生过某事吗”。例如：He cant have forgotten it.他不可能已忘记此事。Can he have gone to his aunts?他有可能到他姑姑家去了吗？I saw Mr. Zhang just now and he couldnt have gone to Beijing.我刚才看见张先生了，他不可能去了北京。Why d

12、oes he know this? Could someone have told him about it?他怎么知道?会是哪个人告诉他了吗?We could not have heard them because of the noise from the river.由于有河水声我们不能听见他们的话。Can he have left already?他会已经离开了吗?They cant have gone out because the lights on.他们不可能出去了，因为灯还亮着。注意：在非正式英语或口语中，偶见到could have done也可用于肯定句，表示推测：She c

13、ould have forgotten to tell him.她可能忘记告诉他了。Tom could have taken the money; he was here alone yesterday.有可能是汤姆把钱拿走了，昨天他单独一个人在这里呆过。In the example mentioned above, either method of construction could have been used.在上面提到的例子中，两种建造方法均可能用过。2. could have done表示未曾实现的可能性该结构仅限于使用could，不用can。表示过去本来有能力、有可能、有打算、有

14、选择做某事的，但实际上却没有那样做。即“过去本来可能做某事，而实际没有做”。通常译为“本来可以”，“本来能够”等。例如：You could have done better, but you didnt try your best.你本可能做得更好，但你没有尽力。We could have got in for nothingnobody was collecting tickets.我们本可以不买票就进去根本没人收票。I could have passed my examination easily but I made too many stupid mistakes.我本可以轻易通过考试

15、，但我犯了太多不该犯的错误。You could have stayed with me when you were in this city on business.在这个城市出差时你本能够和我住在一起的。She could have been seriously injured.她本来可能伤得很重的。Its difficult enough, but it could have been worse.这事情够困难的了，本来可能会更糟呢！I could have given you some hints, but I suppose you thought yourself too grand

16、.我本可以给你点提示的，但是我认为你太自负了。I could have lent you the money. Why didnt you ask me?我本来可以借这笔钱给你的，你为什么不向我提出?You neednt have walked up; you could have taken the lift.你没必要走着上去，你本来可以乘电梯的。有时，也可根据语境译为“好在没有”，“差点”，尤其是当谈论的是不利情况时。如：She felt miserable. She could have cried.她感到很痛苦，她差点哭了。That was a had place to go skii

17、ngyou could have broken your leg.那不是一个滑雪的好地方，好在你没有把腿给摔断。Why did you throw the bottle out of the window? Somebody could have been hurt.你为什么把瓶子扔出窗外呢?好在没有砸伤人。3.could have done除了含有上述的意思外，还表示批评或责备即表示过去本来有责任或义务应该做某事的，但实际上却没有做成，含有批评和责备的意味，通常译为“本来应该”，“本来可以”等，用法同上。例如：You could have helped mewhy did you just

18、sit and watch?你本来可以帮我一把嘛为什么你只是坐在那儿观望呢?I am disappointed that you didnt tell me. You should have told me.你没告诉我，我感到很失望，你本来应该告诉我的。4.could have done用于虚拟语气在虚拟条件句中，当谈论过去的情况时，其句型通常是：主句用“could/would/might +have+过去分词”，if从句用过去完成时。例如：You could have been killed if I hadnt warned you.我如不是警告了你，你就可能丧命了。If he had k

19、nown the facts, he could have told us what to do.如果他了解事实，他是可能告诉我们怎样做的。If you had come sooner, you could have helped us.你如早来一点，就会帮上我们了。I could have told them what happened if anybody had asked me.如果有谁问过我，我可以告诉他们发生了什么情况。四、should have done的用法1. should have done表示“过去本应做某事，但实际没有做”，其否定式shouldnt have done表

20、示“过去不该做某事，但实际却做了”。这种句式含有不满或责备之意，通常可译为“本来应该”；其否定式意为“本来不该”。ought to可以跟should换用，但语气比should强烈。例如：You should have finished your homework.(But you didnt.)你本应该完成你的作业了。（但是你却没有。）You should have reported the matter to the police.你本应该把这件事报告警察。I beg your pardon. I suppose I should have knocked.对不起，我想我应该先敲一下门的。如

21、果是否定式，则表示本来不该发生的情况却发生了。例如：You shouldnt have told her the news.(But you did.)你本不应该把这个消息告诉他。（但你却已告诉。）You shouldnt have opened her letter.你是不应该拆她的信的。She shouldnt have stood in a queue. She should have got tickets from the machine.她本来就不该去排队，她应该在售票机那儿买票。该用法中的should也可换成ought to，意思不变。例如：You should (ought t

22、o) have told us earlier.你应该早点告诉我们的。You shouldnt (oughtnt to) have parked there.你本不该把车停在这里。2.表示对过去情况的主观推测指对可能已经发生的情况作主观猜测，其意为“大概已经”，“应该已经”。例如：The letter should have arrived by now.信函现在该到达了。I wonder why he should have been so angry.我想不通他怎么会这样生气。该用法中的should也可换成ought to，意思不变。例如：The train should (ought t

23、o) have already left.火车大概已经开走了吧。但是，我认为，should表推测时仅限于使用肯定形式，不能用否定形式。否则，就不是推测。这一点跟must表推测的用法是一致的，must一旦使用了否定形式，就不表示推测。You should have no problem with reading this language.读这种语言你应该没问题。The doctor says it will take six weeks and I should be fine by then.医生说需要6周时间，到那时我就会好了。3.表示惊讶对已经发生的情况表示惊讶或不理解，通常含有“竟然”

24、的意味。例如：It is a pity that he should have failed in the exam.他考试竟然没有及格，真是可惜。I cant think why he should have said that it was my fault.我真不明白，他怎么竟然说这是我的过错。Its strange that he should have left without telling us.奇怪，他竟没有和我们说一声就走了。4.用于虚拟语气在虚拟条件句中，当谈论过去的情况时，其句型通常是：主句用“could/would/should /might +have+过去分词”，i

25、f从句用过去完成时。虚拟语气的“should+have+过去分词”结构，仅限于使用第一人称。例如：If I had seen her I should have invited her.我当时要是看到她的话我本会邀请她的。If I had received the present, I should have thanked her.如果我收到了礼物，我是应当向她道谢的。I should not have laughed if I had thought you were serious.如果我想到你是认真的，我就不会笑了。五、neednt have done的用法neednt have do

26、ne表示过去没有必要做某事，意为“本来不必做某事”（但实际做了）。I neednt have taken the umbrella, for the weather is fine.天这么好，我本没必要带雨伞的。You neednt have told her again.I have told her already.你当时没必要再告诉她了。我已经告诉过她了。I neednt have gone to the office yesterday.昨天我没必要去办公室。“need +完成时”仅限于否定句或疑问句，不用于肯定句。又如：I was the first to get there. I neednt have gone