情态动词+have done表推测

情态动词+havedone的用法小结摘要：情态动词have done不仅是高中英语教学的重点和难点，也是高考的重点。

情态动词have done有两大功能：一是表示推测；二是表示虚拟。

关键词：情态动词；推测；虚拟情态动词是高中阶段一个难以掌握的语法项目，且一直是高考的重点和难点。

近年来各省市对情态动词的考查热点之一就是：“情态动词+have done”。

“情态动词+have done”这一结构有两大功能：一是表示推测；二是表示虚拟。

一、用“情态动词+have done”结构表示对过去动作的推测，高考试题中常用过去时态或过去的时间状语给以暗示1.must have done：表示对过去动作的肯定推测，常译作“一定做了……”，语气十分强烈，只能用于肯定句中。

（1）jack described his father，who _______ a brave boy many years ago，as a strong-willed man.（2010年安徽）a.would beb.would have beenc.must bed.must have been（2）—guess what！i have got a for my term paper.（2007年上海）—great！you____read widely and put a lot of work into it.a.mustb. shouldc.must haved.should havekeys：d；c（注意：must have done只能表推测）2.may/might have done表示对过去的可能性推测“过去可能做了某事”，其程度小于must have done，一般也用于肯定句。

如：—i left my handbag on the train，but luckily someone gave it to the railway officials.—how unbelievable to get it back！i mean，someone _______ it.（2011年江苏）a.will have stolenb.might have stolenc.should have stolend.must have stolenkeys：b3.can/could （not）have done意思是“过去（不）可能做过某事”，常用于否定句和疑问句。

（2010山东）2. I_______ have watched that movie —it’ll give me horrible dreams. A. shouldn’t B. needn’t C. couldn’t D. mustn’t 解析：句意应为‚我本来不应该看那部电影的---它会使我做噩梦的。”表示‚本来不应该做而做 了某事‛用shouldn’t have done, 所以A项正确。 答案：A
8) --- John passed the exam, although he didn't study very much for it. --- The exam ________ difficult. A A. can’t have been B. must have been C. couldn’t be D. might have been 9) --- I wonder why they are late. --- They _________ the train. B A. can miss B. may have missed C. could miss D. might miss A 10)--- He _________ to help us yesterday, but he didn‘t. --- You must forgive him. He was ill yesterday. A. should have come B. could have come C. must have come D. can have come
你本来可以做得更好你本来可以做得更好22maymighthave过分分词表示对过去事情的推测一般不用于疑问句虽然表示对过去事情的推测一般不用于疑问句虽然maymight均指过去但might表示推测的可能性和实际情况相反含有责备抱怨之意表示推测的可能性和实际情况相反含有责备抱怨之意译为可能或许本可以已经

情态动词+have done：对过去行为或动作表示推测、评论或判断一、虚拟语气1、should have done：过去本应该做某事却未做否定结构should‘t have done：过去本不该做某事却做了2、ought to have done：过去本应该做某事却未做否定结构oughtn‘t to have done：过去本不该做某事却做了3、need have done：过去本有必要做某事却未做否定结构needn‘t have done：过去本没必要做某事却做了4、could（不能用can）have done：过去本能够做某事却未做否定形式couldn‘t have done没有虚拟语气的用法couldn’t have done只能表推测，=can’t have done：过去不可能做了某事5、might（不能用may）have done：过去本可以做某事却未做否定形式might not have done没有虚拟语气的用法。

might not have done只能表推测，=may not have done：过去可能没有做某事二、推测1、must have done：过去肯定做了某事。

不存在mustn’t have done的形式。

否定或疑问形式须用can(could) have done(不可能，肯定不会)来表示。

2、may/might have done :过去可能做了某事may比might 表示的可能性在说话人看来稍大些。

may/might not have done:过去可能没有做某事3、can/could have done：can have done一般用在否定句和疑问句中,表示不相信或怀疑的态度。

could have done还可以用于肯定句，表示本来可能完成而实际未完成。

PS: 表示推测过去某动作发生的可能性时，就表示的可能性程度而言:mus t＞could＞may＞might 情态动词的回答方式：。

情态动词+have+done是历年高考的重点和难点之一，现将其用法总结归纳如下：一、must+have+done表示对过去事情的肯定推测,译成“一定做过某事”,该结构只用于肯定句.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”。

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、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.本来他能通过考试，但他太粗心五、“may+have+done”表示对发生过的事情的推测，意思是“可能已经”或“也许已经”，用于肯定句中。