情态动词专题精讲.doc

情态动词专题精解一、情态动词的基本用法（一）情态动词的特点1. 没有人称和数的变化。2. 有些情态动词有过去式的变化： will would , can could , may might , dare dared（二）can (could) 1. 表示能力。 Eg: Two eyes can see more than one. 2. 表示允许。 Eg: Can I have a look at your new pen? Can (Could) you lend me a hand? 3. 表惊异、怀疑、不相信等态度。主要用于否定句、疑问句或感叹句中。Eg: Where can (could) they have gone to? He cant (couldnt) be over sixty. How can you be so careless? 4. 表示猜测 (肯定句把握较小；否定句几乎为100%把握) eg:The temperature can fall to 10. You cant be serious.(三)may (might) 1表允许，might是may的过去式; 用在疑问中比may委婉、客气。Eg: You may take whatever you like. He told me that I might smoke in the room. 2. 表可能（事实上）。 语气不肯定。 Eg:He may be at home. 他可能在家。 She may not know about it. I am afraid they might not agree with him. They might be having a meeting, but Im not sure. (三)must1. 表必须（主观意志）eg: We must do everything we can to help him. You mustnt talk to her like that. -Must we hand in our exercise books now? -No, you neednt. / No, you dont have to. /yes,you must.2. 表示很有把握的推断，意为“想必、准是、一定”等，只用于肯定句。have (has)to：eg: have (has)got to 必须, 不得不。过去式为had to。 He must be ill. He looks so pale. She must have a lot of money, for she drives a BMW.(四)shall1. 表征询意见，用于第一称疑问句。 Eg:Shall I get you some tea? Its a fine day. Lets go fishing, shall we?2. 表说话人的意愿，有“命令、允诺、警告、决心”等意思，用于第二、第三人称陈述句。Eg:You shall do as I say. （命令） You shall have the English book as soon as I finish it.（允诺） He shall be sorry for it one day, I tell you. （警告） Everything that he owns shall be taken away from him.（决心）(五)will1. 表意愿，用于各种人称陈述句。Eg: I will do anything for you. If you will read the book, Ill lend it to you. 2. 表请求，用于疑问句。Eg: Dont smoke in the meeting room, will you? Wont you drink some more coffee? 3. 表示某种倾向或习惯性动作。Eg: Fish will die out of water. The door wont open. (六)would1. 表意愿。Eg: They would not let him in because he was poorly dressed. 2. 表委婉地提出请求、建议或看法。Eg: Would you like another glass of beer? 3. 表过去反复发生的动作或过去的一种倾向。Eg: Every time she was in trouble, she would go to him for help.(七)should1. 表义务。意为“应该”，用于各种人称。Eg: You should listen to the doctors advice. 你应该听从医生建议的。 You should study the article carefully. 你应该仔细读那篇文章。2. 表推测，意为“想必一定、照说应该、估计”等。Eg: The film should be very good as it is starring first-class actors. 那部电影想必很棒，都是一流的演员。 They should be home by now. 现在他们应该已经到家了。(八)ought to1. 意为“应该”，口气比should稍重。Eg: Ought you to smoke so much? 你应该抽这样多烟吗？ You ought to write to the mayor. 您应该给市长写信。 2. 表推测，暗含很大的可能。Eg: She ought to know his telephone number. 她应该知道他的电话号码。(九)used to 过去常常, 现在不复发生或存在。Eg:The Greeks used to worship several gods. 过去,希腊人崇奉好几种神。 He used to smoke. 他过去抽烟（现在不抽了）。二、情态动词的推测用法 肯定句中： must (一定)，may (可能)，might/could (也许，或许) 其语气的肯定程度依次递减。其中，might 和could并非过去时态，只是语气较为委婉或可能性较小 对当前行为、情况或状态的推测： must /may /might /could + do/be eg: He must/may/might/could be in the reading room. 他肯定/可能/也许在阅览室里。 I must look funny in this hat. 我戴这顶帽子看起来一定很滑稽。 对此时此刻正在进行的动作的推测： must /may/ might/ could + be doing 想必/可能正在Eg:He must /may/ might/ could be watching TV at this time. 他此时一定/可能/或许在看电视。 They must be waiting for us. 他们肯定在等着我们。 对过去发生的事情的推测： must /may /might /could + have +过去分词 想必/可能已经 Eg: They must have arrived by now. 现在他们肯定已到了。 You look very tired. You must have stayed up last night. 看上去你很疲劳，你昨晚一定熬夜了。 You may have read about it in the papers. 你可能在报上已读到这件事了。 过去的一段时间内一直在进行的动作： must/may /might/ could + have + been +doing 想必/可能一直在Eg:They are sweating all over. They must have been working in the fields. 他们浑身是汗，准是在地里劳动来着。 He may have been waiting for us for an hour. 他可能等我们一小时了。2否定句中： can/could not 不可能，想必不会may/might not 可能不对当前行为、情况或状态的推测： can/could not+动词原形 不可能，想必不会may/might not +动词原形可能不eg:He may not be busy now.也许他现在不忙。 He can not be busy now.他现在一定不忙。 He cant be in the reading room. I saw him on the playground just now. 他不可能在阅览室里，我刚看到他在操场上。对此时此刻正在进行的动作的推测： can/could not + be doing 不可能，想必不会在干某事may/might not + be doing 可能没在干某事eg:They cant be telling the truth.他们不可能在说真话。 They may not be telling the truth.他们可能没在说真话。对过去发生的事情的推测： can/could not + have +过去分词 不可能，想必不会做过某事may/might not + have +过去分词 可能没干过某事eg: He cant have finished the work so soon.这项工作他不可能完成得这样快。 He may not have achieved all his aims. But his effort is a good one. 他可能没达到他的全部目的，但他还是认真做了努力的。过去的一段时间内一直在进行的动作： cant /couldnt/may not have been doingeg:He cant have been waiting for us so long.他不可能等我们那么长时间。3疑问句中： 常用can/could来表示说话人的猜疑、怀疑或不肯定的语气 对当前行为、情况或状态的推测： can/could + 主语+ do/beeg:Where can he be now? 他现在会在哪里呢？ Can it be true?那会是真的吗？ 对此时此刻正在进行的动作的推测： can/could +主语+ be doingeg:Its so late. Can Tom be reading?这么晚了，汤姆还在看书吗？ What can he be doing?他可能在做什么呢？ 对过去发生的事情的推测： can/could +主语+have doneCan she have told a lie?她会不会说谎了？Where can she have gone?她会上哪儿去了呢？三、“情态动词+完成式”的用法1. should(nt) have done表示本该做的事情实际上并未做，或者本不该做的事又做了。 Eg: You should have told me about that. You shouldnt have scolded her like that, she is a little girl,though.2. must have done/cannot have done（may/might have done, couldnt have done）表示对过去情况的肯定或否定推测判断。 Eg：I saw our teacher in the cinema yesterday, so she cant have stayed at home. She was playing with her friends on the field; She must have finished her homework.3. would/should/could/might have done用于与过去事实相反的虚拟语气主句中。 Eg: If I had worked hard when I was at school, I would have passed the exam easily.4. 其它情况 need have done/neednt have done表示不必等。四、情态动词的辨析(一)need和dare1. 用作情态动词eg:Need he go yesterday? 昨天他有去的必要吗? I dont think you need worry. She dare not go out alone at night. How dare you say Im unfair? 2. 用作实义动词eg: She needs the work done before tomorrow. 她必须在明天以前找人完成这项工作。 The table needs painting (to be painted.). I dare say hell come again.（二） can 和be able tobe able to 表示经过努力后, 能够做到; be able to 有多种形式的变化。can 1.表示体力或脑力方面的能力; 2. 表示允许、可能性。could 是can的过去式, 表示过去有能力及过去存在的可能性；用于疑问句表示委婉地提出问题。Eg:1. The fire spread through the hotel very quickly but everyone was able to get out. 2. Will you stay for lunch? Sorry, I cant. My brother is coming to see me. (三)must和have tomust表示主观意志，而have to表示由于客观因素。Eg:I told her that she must give up smoking. We had to get everything ready that night.(四)would和used to1）used to “过去常常”, 与现在事实相反; 2)would表过去意愿。Eg:People used to think that the earth was flat. She would go out for a walk in the morning when she was in the country. 五、易错点点拨：1情态动词无论是表达“推测和可能性”，还是表达“虚拟”这一概念，只要是对过去已经发生的事情进行描述，一律用“情态动词+have done”这一结构；对现在或将来的事情进行描述，用“情态动词+动词或系动词原形”。2should (not) / ought (not) to在中表示根据常规或常识推测，表示“某事应该或不应该发生”，语气比must或cant / couldnt稍弱。3. can, could表达推测时，一般用于疑问句和否定句中；can用于肯定句中表示一种理论上的可能性，并不牵涉是否真的会发生，在这种用法中can只能与动词原形连用；could用于肯定句中，语气比may/ might更弱。4. must表达“情感、态度、语气”主要有以下用法：(1) 表示主观的义务和必要，主要用于肯定句和疑问句，意思为“必须，得，要”；由must引起的疑问句，肯定回答要用must或have to， 否定回答要用neednt或dont have to,意思是“不必”。另外，must与have to都可以表示“必须”这一含义。must表示一种主观的需要，而have to表示一种客观的需要，意思是“不得不”，其否定形式是don have to。(2) must用于条件句或疑问句中，可以用来表示责备、抱怨的感情色彩，意思为“偏要，硬要、干嘛”。5. 在虚拟条件句中用以加强假设语气，表示“与将来事实相反的假设”，用 If+主语+ should +动词原形，当“万一(会)”讲。这时可省略if，将should提到句首，变为倒装句式。If it should rain(=Should it rain) tomorrow, I would stay at home. 万一明天下雨的话，我就待在家里。6. should还可以用来表示说话人对某事不能理解、赶到意外、惊异等意思，译为“竟然，竟会”。 You cant imagine that a well-behaved gentleman should be so rude to a lady.六、高考链接2012年高考题【2012江西卷】22We have bought so much food now that Suzie wont be with us for dinner.Amay notBneedntCcantDmustnt 22答案：B考点：考察情态动词的用法。解析：may not不可以，neednt不需要，cant不可能， mustnt绝不可能。本句句意为：既然Suzie不和我们一起吃晚饭，所以我们就不需要买这么多食物。2012湖南高考真题29. Sorry, I am too busy now. If I _ time, I would certainly go for an outing with you. A. have hadB. had hadC. haveD. had 2012湖南高考真题29|D|此题考查条件状语从句中的虚拟语气，从句中用一般过去时表现在的假设。动词的时态 条件状语从句中的虚拟语气 一般过去式表对现在的假设 【2012重庆卷】25.-_you interrupt now? Cant you see Im on the phone? -Sorry Sir, but its urgent. A. Can B. Should C. Must D. Would25.【考点】情态动词用法【答案】 C【解析】句意：“你现在一定要打断我吗？难道你不能看到我在打电话吗？对不起，先生，事情很急。”根据语境结合选项的词义，C选项符合题意。因此，正确答案为C选项。【2012辽宁卷】24. One of our rules is that every student wear school uniform while at school. A. might B. could C. shall D. will24、【考点】情态动词【答案】C【解析】Shall用于第二、第三人称，表示说话人给对方命令、警告、允诺或威胁。这儿是说根据学校规定学生在校时都必须要穿校服。1【2012四川卷】9. I got close enough to hear them speaking Chinese, and I said “Ni Hao ” just as I _ do in China.A. must B. might C. can D. should 19.【答案与解析】 B 本题考查情态动词。句意为：我靠他们足够的近以听见他们说汉语，而且我会像我在中国可能做的那样说“你好”。might表示“可能”。故选B。【2012陕西卷】17. If may car _more reliable, I would have driven to Lhasa instead of flying last summer.A. was B. had beenC. should be D. would beA102012陕西卷【答案与解析】B 考查虚拟语气。根据主语的谓语动词可知题干是表示与过去事实相反的虚拟语气，从句谓语动词用had done，选B。【2012陕西卷】23.I_ thank you too much for all your help to my son while we were away from home. A. wont B. cant C. can D. will A102012陕西卷【答案与解析】B 考查情态动词。所填情态动词与too 构成固定句型cant/couldnt too，意思是：再都不为过，选B。【2012北京卷】33. We _ the difficulty together, but why didnt you tell me?A. should face B. might face C. could have faced D. must have faced33. C。虚拟语气考点，对过去的虚拟，本能。【2012北京卷】35. Dont handle the vase as if it _ made of steel.A. is B. were C. has been D. had been35. B。虚拟语气考点，对现在的虚拟用were。【2012全国II】17. Im going to Europe on vacation together with John if I _ find the money.A. can B. might C. would D. need【答案】A【解析】此处考查了can的本意“能”，表示“能力”。句意：我要和John一起去欧洲度假，如果我能找到钱。【考点定位】考查情态动词的用法。15. 【2012天津卷】 We wouldnt have called a taxi yesterday if Harold _us a ride home.【D】A. didnt offer B. wouldnt offer C. hasnt offered D. hadnt offered8【2012天津卷】 Its quite warm here; we _turn the heating on yet.【C】A. couldnt B. mustntC. neednt D. wouldnt【2012全国新课程】30. I use a clock to wake me up because at six oclock each morning the train comes by my house.A. couldnt B. mustnt C. shouldnt D. neednt【答案】D【解析】此处考查情态动词，neednt+动词原形表示：没有必要做某事。句意：我没有必要用闹钟唤醒我，因为每天早上6点火车都经过我的房子。【考点定位】考查情态动词的用法。【2012山东卷】30. If we _ adequate preparations, the conference wouldnt have been so successful. A. havent made B. wouldnt makeC. didnt make D. hadnt made30.【答案】D【解析】在虚拟条件句中，表示与过去事实相反的情况，从句用过去完成时，主句用would have done的形式。句意：如果我们没有做好充分的准备，会议就不会这样成功。【考点定位】考查虚拟语气的用法。【2012福建卷】31. We lost our way in that small village, otherwise we_more places of interest yesterday.A. visitedB. had visitedC. would visit D. would have visited【考点】本题考查虚拟语气的用法【答案】D【解析】本题关键是从时间状语yesterday知道是对过去的虚拟，前半句是个过去的客观事实“我们在那个小山村迷路”，otherwise否则后半句是用对过去的虚拟would have done，答案为D项。对虚拟语气的做法主要是看时间状语或是看里面的关键词是对什么时间的虚拟，这就很容易了。【2012江苏卷】35. Happy birthday!Thank you! Its the best present Ifor.A. should have wishedB. must have wishedC. may have wishedD. could have wished35. 【考点】情态动词+完成式 【答案】D【解析】A项意为“本应该期望而实际上并非如此”；B项意为“一定希望”；C项意为“也许希望”；D项意为“可能希望”。句意为：生日快乐！谢谢你！这是我所能期望的最好的礼物了。根据句意可知，应选D项。【试题延伸】.Oh, Im not feeling well in the stomach. I_so much fried chicken just now. A. shouldnt eat B. mustnt have eaten C. shouldnt have eaten D. mustnt eat 【解析】该句所表达的意思是刚才我不因该吃那么多炸鸡，而实际上是吃了那么多，可以判断用shouldnt have eaten. 答案是 C。 【2012江苏卷】28. Days later, my brother called to say he was all right, butsay where he was.A. mustntB. shouldntC. wouldntD. mightnt28. 【考点】情态动词would 【答案】C【解析】mustnt意为“禁止”；shouldnt意为“不应该”；wouldnt意为“不愿意”；mightnt意为“或许不”。句意为：几天后，我哥哥打电话说他一切很好，但不愿意说他在哪儿。根据句意可知，应选C项。【2012安徽卷】31. Grace doesnt want to move to New York because she thinks if she there, she wouldnt be able to see her parents very often.A. lives B. would live C. having asked D. Were to liveD 在表示将来的情况下，主句中第一人称可用should，其他人称用would；从句中任何人称都用should,不可用would.2011年高考题1.（2011辽宁卷）21. If you _ go, at least wait until the storm is over.A. can B. may C. must D. will答案与解析：选C。句意为：如果你非要走的话，至少等到暴风雨结束。根据语境可知，must（一定要）正确。can 能够；may或许；will将要。2. （2011浙江卷）11.Hows your new babysitter?We _ ask for a better one ,All our kids love her so much.A. shouldB. might C. mustnt D. couldnt答案与解析：选D。根据语意“你们的新保姆怎么样？我们不能再要求更好的了，孩子们都很喜欢她”可知，这里用couldnt表示“不可能”，should应该；might可能；mustnt禁止；都不符合题意。3.（2011北京卷）24.I dont really like James. Why did you invite him?Dont worry. He_come. He said he wasnt certain what his plans were.A. must not B. need not C. would not D. might not答案与解析：选D。根据句意可知，James不太确定他的计划，他可能不来。might not可能不。4.（2011江西卷）23._ be the postman at the door, Its only sis oclock.A. mustnt B. cant C. wont D. neednt答案与解析：选B。门口不可能是邮递员，（现在）才六点钟。对现在情况的否定推测，由Its only six oclock分析可知，应用cant（不可能）；mustnt禁止；wont不会；neednt 不必；均不符合句意。5.（2011四川卷）20.The police still have I found the lost child, but theyre doing about they_.A. can B. may C. must D. should答案与解析：选A。do all they can做他们能做的一切。句意为：尽管警察还没有找到失踪的孩子，但是他们正在竭尽所能。6.（2011全国II）8. If you _ smoke, please go outside.A. can B. should C. must D. may答案与解析：选C。句意为：如果你非要吸烟，请到外面。此处must表示“非要”。7.（2011陕西卷）24.Will you read me a story, Mummy? OK. You _ have one if you go to bed as soon as possible.A. might B. must C. could D. shall答案与解析：选D。“妈妈，给我讲个故事好吗？”“好的，如果你尽快上床睡觉我就给你讲一个。”shall用于陈述句的第二、三人称，表示说话人的意图、允诺、警告、命令等。8.（2011重庆卷）25.Why didnt you come to Simons party last night? I want to, but my mom simply _ not let me out so late at night.A. could B. mightC. would D. should答案与解析：选C。问话人询问为什么没有参加昨晚Simon的聚会，答话人回答说自己想去，但是妈妈只是不想让自己在这么晚的时候出去。此处would表示的是过去的意愿。9.（2011湖南卷）28 .-No one _ be compared with Yao Ming in playing basketball.-Oh, you are really his big fan. Acan B. need C. must D. might 答案与解析：选A。can在此表示能力。句意为：在打篮球方面，无人能与姚明媲美。你真是他的铁杆粉丝。10.（2011福建卷）25.-Shall I inform him of the change of the schedule right now? -I am afraid you _, in case he comes late for the meeting.A. will B. must C. may D. can答案与解析：选B。依据in case he comes late for the me