语法专题情态动词和虚拟语气ppt课件.ppt

,情态动词和虚拟语气,Grammar,Modal Verb and the Subjunctive Mood,山丹一中 王秋莲,1. He must have gone to Beijing.2. The door was locked. She couldnt have been at home.3. They may be still waiting for us.,他一定已经去北京了。,门是锁着的， 所以她不可能在家。,他们可能还在等我们呢。,4. He might have read about the news in the newspaper.5. You should have told him a week ago.6. Can you give me some suggestions?,他可能已经从报纸上知道这个消息了。,你本来应该在一周前告诉他的。,你能给我一些建议吗？,什么是情态动词？ (Modal Verbs),情态动词表示说话人对某一动作或状态的态度（感情或语气），表示“可能、需要、可以、必须、应当”等。 但是本身词义不完全，不能单独作谓语动词。,情态动词的语法特征,1. 情态动词不能单独做谓语，除ought和have外，后面只能接不带to的不定式（即动词原形)。,2. 情态动词没有人称和数的变化，但有 些情态动词没有过去式，如must; 有些有过 去式，如：cancould maymight willwould shallshould have tohad to,只作情态动词的 can/could, may/might, ought to, must可情态可实义的 need, dare/dared可情态可助动词的 shall/should, will/would,3. 情态动词的“时态”形式并不是时间区别 的主要标志，不少情况下，情态动词的 现在式形式和过去式形式都可用来表示 现在时间、过去时间和将来时间。,Objectives: 1. 情态动词的基本用法 2. 情态动词用于表示推测和不表示推测的用法 3. need 和 dare 的用法,1. can 的用法,1.I can lift the stone. The girl can dance very well. 2.You can borrow my bike. Can I sit here? 3.Can it be true? It cant be true.,. 1. 能力（体力或脑力） 2.请求，允许或许可 3. 猜测（用于疑问句、否定句）,.can与be able to的区别,1.He says he will be able to be home for Christmas.2.I was able to help you yesterday.3.This problem can be settled at once.,can有现在时、过去时；可用于被动语态。be able to有各种时态；指某一次动作；不可用于被动态。,can和could,一、情态动词的基本用法,2. could的用法： A. could 是can的过去式, 表示与过去 有关的能力和推测: We all knew that the young man couldnt be a doctor. B. could可以代替can表示请求, 但语气较can客气,委婉: Could you lend me your dictionary? Could I use your bike?3. can和could接动词的完成形式，表示可能已经做某事。can用在否定和疑问句中, 表示不相信、怀疑等态度。 They cant have gone out because the light is still on.,常用句型 1. could have done 2. can/could have done ? 3. cant/couldnt have done,1.She could have explained the matter.2.Can she have told a lie?3. Where can/could he have gone?4.He cant/couldnt have said that.5.She cant/couldnt have been at home all this time.,本来能够做可能做过吗？ 不可能做过,may 的用法： 1. 表示请求、允许：比can较为正式， can较口语化 May I come in? You may go now. You may not smoke in the classroom. 2. 表示说话人的猜测: “也许” “可能”: 通常只用于肯定句和否定句中。 I believe the man is from England. But I may be wrong. The guest may arrive this afternoon. The story may or may not be true. 但是在否定句中，意义是不一样的，如： He cant know the truth. He may not know the truth.,may 和 might,他不可能知道真相。他可能不知道真相。,在肯定句中，may 的可能性比can 高，may 表示现实的可能性，can 表示理论上的可能性。如： The road may be blocked. The road can be blocked.这条路可能不通了。 这条路可能会是不通的。 在疑问句中，表示可能性用can。 如：Where can he be? 他会在哪呢？ Can that be true? May that be true? 3. 表示祝愿; 但语气较正式: eg. May you succeed! May you have a good journey!,might 的用法有: might 一般不表示过去的可能或者许可，表示现在的许可，语气比may 较委婉，一般多用于疑问句和肯定句。如要表示过去的可能可以用could, 表示过去的许可也可以用was( were) allowed to 或者 had permission to 。表示现在的可能，其可能性要比 may 小。 如: Might I have a word with you? 我可以和你说句话吗？ He might go home tomorrow. 说不定他明天会回家。,常用句型： may have done 可能做过,1.she may have missed the bus.2.It may have drizzled during the night.,1. will是助动词还是情态动词？ will用于构成将来时是助动词。用于表示“意志”“决心”“请求”是情态动词。would亦同理。 eg. I will tell you something important. 我要告诉你一件重要的事情。（助动词） Will you tell her that Im here? 请您告诉她说我在这儿，好吗？（情态动词） 2. 在疑问句中用于第二人称，提出请求或询问。 eg: If you want help, let me know, will you? 如果你需要帮助, 让我知道, 好吗? Will you type this, please? 请把这个打一下，好吗？ Wont you sit down? 请坐下，好吗？,will 和would,3. would比will客气委婉。 eg: Would you help us, please? 请您帮助我们，好吗？Id go there with you. 我要和你一块到那儿去。 Your teacher wouldnt allow it. 老师不会允许这件事。,（表请求）,（表意愿）,（表许可）,1. shall用于构成将来时是助动词。 shall用于征求对方的意见，表示 “决心” 是情态动词。 Perhaps I shall pay a visit to England this winter. 可能今年冬天我会去英国观光。（构成一般将来时, 助动词） Shall we go by train, Mom? 妈妈，我们乘火车去好吗？ （用于征求对方的意见，情态动词） I shall go at once. 我必须立即去。 （表 “决心”，情态动词）,shall 和 should,2. should表示义务、建议、劝告，意为“应该”。 You should keep your promise. 你应该遵守诺言。 “should+ have+过去分词” 表示本应该在过去做但没有做。 She should have passed the exam. 她应该通过考试的。,should 和ought to 都为“应该”的意思，可用于各种人称。ought to 的语气稍重一些。 You ought to (should) follow your teachers advice.但是should还可用于1. 主语的义务或责任，如： You should take care of your sister. 你应当去照顾你妹妹。2. 或指出一个正确、明智的动作： They shouldnt allow parking here；the street is too narrow 这儿不该允许停车；马路太窄了。,ought to 和 should,should 和ought to 后面跟动词不定式的完成式, 其肯定句表示”过去应该做而未做”, 其否定句则表示”过去不该做但做了”。You should/ought to have made the decision a week ago.I shouldnt have made such a foolish mistake.,注意,must的用法 1. 表示必然性。 eg: We must all die. 人总要死的。 2. 表示强制或者义务。 eg: You must get up early. 你必须早起来。,must 和 have to,3. 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haveto,否定回答要用neednt或donthaveto, 意思是“不必” ； must的否定形式mustnt表示禁止，意思是“不能, 不许”。如： MustIfinishthetaskrightnow? 我现在必须完成这个工作吗？ Yes, youmust./Yes,youhaveto. 是的。 No, you neednt. / No, you dont have to. 不, 不必。,haveto的用法1. must表示一种主观的需要，而haveto表示一种客观的需要，意思是“不得不”。口语中常翻译成“得”。如：I have to attend an important meeting this afternoon. 今天下午我得参加一个重要的会议。 Mother is out, so I have to look after the shop. 妈妈不在家，因此我得照看商店。 2. haveto的否定形式是dont have to, 相当于neednt。 如：They dont have to buy a computer at present. 他们目前没有必要买电脑。, _ I go out to play, mum? No, you _. You should do your homework first. A. Might; wouldnt B. May; had better not C. Must; mustnt D. Need; mustnt,课堂练兵,2. Where is Emma? I cant say for sure where she is, but she _ be out shopping. A. can B. should C. must D. may3. The room is in a terrible mess; it _ cleaned. A. cant have been B. couldnt be C. may have been D. would be,4. May I sit beside you, sir? Sorry, you _. Look, my daughter is coming. A. cant B. mustnt C. neednt D. shouldnt,5. She looks very happy. She _ have passed the exam. I guess so. Its not difficult after all. A. should B. could C. must D. might6. Ive taken someone elses green sweater by mistake. It _ Harrys. He always wears green. A. has to be B. will be C. mustnt be D. could be,情态动词,表示推测,不表示推测,can couldmay mightshall shouldmust will wouldought to,have to dare (darent)need (neednt),二、表示推测情态动词的重要用法.,1. You must be Mr Smith-I was told to expect you here.2. He must have known what we wanted.3. We may have read the same report.4. He cant have slept through all that noise.5. Theres someone outside-who can it be?6. What can they be doing?7. These pills might help to cure your disease.8. You could be right, I suppose.,表示推测情态动词的重要用法.,肯定的推测可能的推测否定的推测疑问的推测,must/should,对将来 对现在 对过去,情态动词,may, might,cant, couldnt,can, could,+ V. + V. + have done常见must be + be doing,+ V. + V. + have done + be doing 可以用not表示“可能不”,+V. + V. + have done + be doing,+ V. + V. + have done + be doing,1. I dont know where she is, she _ be in Wuhan. 2. At this moment, our teacher _ our exam papers. 这时，我们老师必在批改试卷。 3. The road is wet. It _ last night. (rain) 4. Your mother _ for you.你妈妈一定一直在找你。,may,must be marking,must have rained,must have been looking,高考考题:1. I thought you _like something to read, so I have brought you some books. A. may B. might C. would D. must 2. Where is my pen? I _it. A. might lose B. would have lost C. should have lost D. must have lost3. I didnt hear the phone. I _asleep A. must be B. must have been C. should be D. should have been,B,D,B,4. -There were already five people in the car, but they managed to take me as well. -It _a comfortable journey A. cant be B. shouldnt be C. mustnt have been D. couldnt have been 5. Its nearly seven oclock . Jack _be here at any moment. A. must B. need C. should D. could,D,C,不同的“肯定”程度可按下列层次排列： He is at home. (事实) He must be at home.（非常肯定的推断） He could be at home.（很可能） He ought to be at home.（很可能） He may be at home.（仅仅可能而已） He might be at home.（或许, 非常不确定） He might not be at home.（也许不在家）He may not be at home. （比might可能） He couldnt be at home.（很可能不在家） He cant be at home.（一定不在家）He isnt at home.（事实）,在不表示推测的情态动词中, 我们要注意以下考点:,1. 表示能力、许可的情态动词的用法。2. 表示否定的情态动词的用法。3. shall 和 will 的多种意义的区别。4. 情态动词短语的使用。5. 虚拟语气中情态动词的使用。,表示能力: can, could, be able to *be able to 能用于各种时态。 can / could 只能表示现在或过去的能力。 *was / were able to : “设法做成某事” 相当于 managed to do sth. succeeded in doing sth.。,1. 表示能力、许可的情态动词的用法。,1. A computer _ think for itself; it must be told what to do. A. cant B. couldnt C. may not D. might not,2. The fire spread through the hotel very quickly but everyone _ get out. A. had to B. would C. could D. was able to,A,D,3. They will _ run this machine on theirown in three months.A. can B. could C. may D. be able to4. That big cinema _ seat 2,000 people.A. can B. should C. ought to D. is able to,D,A,表示许可: may / might, can / could * might, could 比较委婉, 一般多用于疑问句.* can, may 表达的语言比较随便.* 在以could, might 表示征询对方意见 或表示请求时，回答应相应使用can, may.,5. Could I borrow your dictionary? Yes, of course you _. A. might B. will C. can D. should6. Might I watch TV after supper? Yes, you _. A. may B. must C. might D. can,C,A,2. 表示否定的情态动词的用法: 部分情态动词的否定式是情态动词中的考点之一。,mustnt 不准, 禁止 neednt 没必要 ( = dont have to )cant 不能; 不可能may not 不可以; 可能不shouldnt 不应该 ( = ought not to ),7. You _ return the book now. You can keep it till next week if you like. A. cant B. mustnt C. neednt D. may not8. Johnny, you _ play with the knife, you _ hurt yourself. A. wont ; cant B. mustnt ; may C. shouldnt ; must D. cant ; shouldnt,C,B,9. -Will you stay for lunch? -Sorry, _. My brother is coming to see me. A. I mustnt B. I cant C. I neednt D. I wont10. -May I pick a flower in the garden? - _. A. No, you neednt B. Not, please. C. No, you mustnt D. No, you wont,B,C,情态动词：shall, will 的多种意义:,shall / will+ 动词原形:,* shall 可表示必须、命令、 警告或征询意见.,* will 可表示意愿、常出现的动作、在疑问句 中表示请求和建议.,* 均可表示将来。 过去时为 should, would.,3.,11. He _ be punished if he disobeys. 如果他不服从, 就要受到惩罚.12. We are not going to quarrel at all if you _ only let me speak. 只要你让我说话, 我们根本就不会吵架.13. -Sir, _ he go or stay? -Let him go. A. will B. shall C. might D. could,shall,will,B,4. 情态动词短语的使用:,would like to dowould rather dowould rather + 从句would prefer to do.had better do.,改错:1. Would you like having some tea?2. Id prefer going to the lecture this evening.3. Id rather you to go to the meeting.4. He would rather to die than to give in.5. Youd better to have your hair cut today.,Would you like to have some tea?,Id prefer to go to ., you went to .,He would rather die than give in.,Youd better have .,5. 用于虚拟语气的情态动词:,should might could would,情态动词考题:,1. Put on more clothes. You be feeling cold with only a shirt on. A. can B. could C. must D. would2. Must I drive to his house and pick up the children? No, . A. you shouldntB. you might not C. you neednt D. you mustnt,C,C,3. We didnt see Tom at the meeting yesterday. He it. A. mustnt have attended B. cannot have attended C. neednt have attended D. would have not attended4. We play chess than bridge. Some of us dont know how to play bridge. A. had betterB. would better C. would rather D. had rather,B,A,5. There is someone knocking at the door. it be Tom? A. can B. must C. should D. ought to6. Two year ago, my husband bought me a bicycle. If you live in town, it is often faster than a car and you worry about parking. A. must notB. may not C. should notD. dont have to,A,D,I darent ask her for a rise. 我不敢请求她加薪.How did you dare to tell her that? I wonder whether he dare stand up in public. I dont know how she dares to wear that dress. Do you need any help?I wonder whether he need send it immediately.I need hardly tell you that the work is dangerous.The garden doesnt need watering at the moment.You neednt finish that work today.,可兼做行为动词的情态动词：need 、 dare,情态动词 (+动词原形),行为动词,.,need,dare,1.无人称和数的变化;,2.尤其用于：,*否定句及疑问句中;,*在if/whether之后;,*或与hardly, never, no one, nobody连用;,3.常以neednt 和darent 的形式出现;,4.dare有其过去时dared.,多用于肯定句; (sb.) need to do dare to do(sth.) need to be done (sth.) need doing,dare可用实义动词和情态动词，用作情态动词时，意思是“敢”，其后接动词原形，通常只用于否定句或疑问句以及if或whether之后，一般不用于肯定句。如：Dare you tell her the truth? 你敢告诉她事实真相吗？I dont know whether he dare try. 我不知他是否敢试一试。I darent ask her for a rise. 我不敢要求她加薪。,dare用作实义动词时意为“敢于”，可以有各种词形变化，可用于各类句型（肯定句、否定句、疑问句及各类从句等），其后多接带 to 的不定式，有时 to 也可省去（尤其是在否定句或疑问句），可用于非谓语形式，完成时态等。如：We must dare to think, speak and act. 我们必须敢想、敢说、敢做。I wonder how he dares (to) say such things. 我纳闷他怎么竟敢说出这样的话来。,情态动词dare可以有过去式dared，但也可以直接用dare表示过去式，或后接动词完成式。如：That was why he dared do so. 那就是他为什么敢这样做的原因。Mother dare(d) not tell father shed given away his old jacket. 母亲不敢告诉父亲她把他的旧上衣送人了。,dare的过去式问题,dare后通常不接动词的进行式。,注意对need问句的回答:-Need I finish the work today?-Yes, _. No, _. No, _.,you must,you neednt,you dont have to,neednt 对其它情态动词的回答:-Shall I tell John about it?-No, you _.-Must we do it now? -No, you _.,neednt (dont have to),neednt (dont have to),判断正误:,How dare you say such a thing? How dare you to say such a thing?,He darent to speak English before such a crowd, did he?He darent speak English before such a crowd, dare he?,Nobody need to be afraid of catching the disease.Nobody need be afraid of catching the disease.,These dishes need be cleaned carefully.These dishes need to be cleaned carefully.These dishes need cleaning carefully.,neednt 对其它情态动词的回答: -Shall I tell John about it? -No, you _. -Must we do it now? -No, you _.,neednt (dont have to),neednt(dont have to),虚拟语气的“四种形式”及“三点注意”,虚拟语气1） 概念 虚拟语气用来表示说话人的主观愿望或假想，所说的是一个条件，不一定是事实，或与事实相反。 2） 在条件句中的应用 条件句可分为两类，一类为真实条件句，一类为非真实条件句。非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。,一、掌握虚拟语气的四种主要形式（1）条件从句+主句（2）名词性从句常用虚拟语气的句型（3）wish, as if ，if only及would rather 的虚拟形式（4）It is time that 的虚拟形式二、注意虚拟语气的三种活用现象（1）含蓄条件句（2）时间错综句（3）虚实错综句,1.The rice _ if you had been more careful. A. would not be burning B. would not burn C. would not have burnt D. would not burnt2.If my lawyer _ here last Saturday, he _ me from going. A. had been ; would have prevented B. had been ; would prevent C. were ; would prevent D. were ; would have prevented3.I didnt see your sister at the meeting. If she _ she would have met my brother. A. has come B. did come C. came D. had come4._ for the free tickets, I would not have gone to the films so often. A. If it is not B. Were it not C. Had it not been D. If they have not5.You didnt let me drive. If we _ in turn, you _ so tired. A. drove ; didnt get B. drove ; wouldnt get C. were driving ; wouldnt get D. had driven ; wouldnt have got,C,A,D,C,D,6.If she had worked harder, she _. A. would succeed B. had succeeded C. should succeed D. would have succeed7. If he _, he _ that food. Luckily he was sent to the hospital immediately. A. was warned ; would not take B. had been warned ; would not have taken C. would be warned ; had not taken D. would have been warned ; had not taken8.If it _ tomorrow, they would not go there by bike. A. will rain B. rains C. would rain D. should rain9._ it rain tomorrow, we would have to put off the visit to the Yangpu Bridge. A. Were B. Should C. Would D. Will10.If I _ you, I would not do it. A. am B. were C. shall be D. being,D,B,D,B,B,1. 动词 + 宾语从句 一个坚持：insist; 两个命令：order, command; 三个建议：suggest, propose, advise; 四个要求：desire, demand, ask, require I propose that we (should) set a dead line for handing in the plans. I suggest that we (should) set off at once. I insisted that we (should) decide what to do with him.,虚拟语气形式：(should) + 动词原形,2. It is (was) + 上述动词的过去分词 + that 主语从句 It is demanded that he (should) leave at once. It is requested that she (should) give a performance at the party.3. It is (was) + important / necessary / better / strange / surprising / natural / possible / a pity / no wonder + that 主语从句 It is be