情态动词modal verbs情态动词的基本用法特点情态动词的基本用法特点1） 情态动词不能表示正在发生或已经发生的事情态动词不能表示正在发生或已经发生的事 情，只表示期待或估计某事的发生。情，只表示期待或估计某事的发生。2） 情态动词情态动词 除除 ought 和和 have 外，后面只能接不带外，后面只能接不带 to 的不定式。的不定式。3） 情态动词没有人称，数的变化，即情态动词第情态动词没有人称，数的变化，即情态动词第 三人称单数不加三人称单数不加-s。4） 情态动词没有非谓语形式，即没有不定式，分情态动词没有非谓语形式，即没有不定式，分 词，等形式。词，等形式。 表示能力表示能力: can, could, be able to *be able to 能用于能用于各种时态各种时态。 can / could 只能表示只能表示现在现在或或过去过去的能力。的能力。 *was / were able to : “设法做成某事设法做成某事” 相当于相当于 managed to do sth. succeeded in doing sth.。1. 表示能力、许可的情态动词的用法。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 not2. The fire spread through the hotel very quickly but everyone _ get out. A. had to B. would C. could D. was able toA D 3. They will _ run this machine on their own in three months.A. can B. could C. may D. be able toD 表示许可表示许可: may / might, can / could * might, could 比较比较委婉委婉, 一般多用于一般多用于疑问句疑问句.* can, may 表达的语言比较随便表达的语言比较随便.* 在以在以could, might 表示表示征询对方意见征询对方意见 或或表示请求表示请求时，回答应相应使用时，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. canC A 2. 表示否定的情态动词的用法表示否定的情态动词的用法:mustnt不准不准, 禁止禁止 neednt没必要没必要 ( = dont have to )cant不能不能; 不可能不可能may not不可以不可以; 可能不可能不shouldnt 不应该不应该 ( = ought not to )wont/ wouldnt 不愿意不愿意darent 不敢不敢can/may/must/need 问句的回答方式问句的回答方式Can/Could you do sth.Yes, I/we/can/couldNo, I wecant/ couldntMay I do sth.?Yes ,No ,you Must I /we do sth.?Yes, No you Need I do sth.?Yes ,No, you 疑问句式肯定句式否定答式you may.mustnt/may not.you mustneednt/dont have to.you must.neednt/dont have 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 ; shouldntC 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 wontB C 表示推测表示推测情态动词的重要用法情态动词的重要用法. .肯定的推测肯定的推测可能的推测可能的推测否定的推测否定的推测疑问的推测疑问的推测 must/should 对将来对将来 对现在对现在 对过去对过去情态动词情态动词may, might cant, couldntcan, could + V. + V. + have done常见常见must be + be doing + V. + V. + have done + be doing 可以用可以用not表示表示“可能不可能不” +V. + V. + have done + be doing+ V. + V. + have done + be doing1. 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. 1. I dont know where she is, she _ be in Wuhan. 2. At this moment, our teacher _ our exam papers. 这时，我们老师想必在批改试卷。这时，我们老师想必在批改试卷。 3. The road is wet. It _ last night. (rain) 4. Your mother _ for you.你妈妈一定一直在找你。你妈妈一定一直在找你。maymust be markingmust have rainedmust have been looking5. Philip _ seriously in the car accident. 菲利普可能在车祸中受了重伤菲利普可能在车祸中受了重伤.6. -Linda has gone to work, but her bicycle is still here.-She _ (go) by bus.7. Mike _ his car, for he came to work by bus this morning.迈克一定还没有找回他的车，因为早上他是坐迈克一定还没有找回他的车，因为早上他是坐 公共汽车来上班的。公共汽车来上班的。may (might) have been hurtmay (might) have gonecant have found情态动词情态动词+完成式：完成式：1. must have done2. may/might have done3. cant couldnt jave done4. should /ought to have done5. shoulnt/oughtnt to have done6. could have done7. neednt have done8. would rather have done1. The ground is rather wet, so it _ have rained last night, didnt it?2. Tom _ have gone to Shanghai, but Im still not sure about it.3. The ground is very dry, so it _ have rained last night.4. Someone must have broken into our bedroom. Who _ have done it?5. I really regretted wasting the hours when I _ have studied hard, but it was too late.mustmaycantcouldshould6.Your home is not far from your school, so you _ have left in such a hurry then.7. I _ have come to help you with your English, but I was too busy at that time.8. -I paid a visit to New York last month and we stayed at a nice hotel.-Oh,you _have stayed with Barbara.She is always willing to do you a favour.couldneedntwould rathershall和和will的比较的比较比较内容比较内容肯定句肯定句疑问句疑问句shall表示表示“威胁威胁”、“警告警告”、“允允诺诺”的语气的语气与第一、三人称与第一、三人称连用，表示征询连用，表示征询对方的意见对方的意见Will/would 1）表示）表示“习惯习惯”2）表示）表示“愿意愿意/望望”3）表示）表示“必然性必然性”与第二人称连用，与第二人称连用，表示征询对方的表示征询对方的意见意见1. If you _follow my advice, I _ offer you some help.2. _ you meet him right now or _ he wait outside, sir?willshallWillshall11. He _ be punished if he disobeys. 如果他不服从如果他不服从, 就要受到惩罚就要受到惩罚.12. We are not going to quarrel at all if you _ only let me speak. 只要你让我说话只要你让我说话, 我们根本就不会吵架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. couldshallwillB 14. The door _ open. 这门经常打不开这门经常打不开.15. Ronald _ stay in his small garden for a long time every day in the past. A. could B. might C. should D. would16. You _ have the book after I read it. 我看完以后一定把这本书给你我看完以后一定把这本书给你.wontD shallwould 和和 used to的比较的比较1、would 主要表示过去一段时间内的某种主要表示过去一段时间内的某种习惯，常与表示过去的时间状语连用，意为习惯，常与表示过去的时间状语连用，意为“总要，总是总要，总是” used to 主要表示过去存在但是现在已主要表示过去存在但是现在已不再存在的习惯，意为不再存在的习惯，意为“过去常常过去常常”。On Sundays he _ go to call on the old man when he was young.I _ get up late, but now I have got used to getting up very early.Xiao Li _ be a model worker. He is now a university student.wouldused toused to可兼做行为动词的情态动词：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 .needdare 1.1.无人称和数的变化无人称和数的变化; 2.2.尤其用于：尤其用于：* *否定句及疑问句中否定句及疑问句中; ;* *在在if/whetherif/whether之后之后; ;* *或与或与hardlyhardly, , nevernever, , no oneno one, , nobodynobody连用连用; ; 3.3.常以常以neednneednt t 和和darendarent t 的形式出现的形式出现; ;4.dare4.dare有其过去时有其过去时dareddared. . 多用于肯定句多用于肯定句; (sb.) need to do dare to do(sth.) need to be done (sth.) need doing I darent ask her for a rise. 我不敢请求她加薪我不敢请求她加薪.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.判断正误判断正误: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.情态动词短语的使用情态动词短语的使用:would like to dowould rather dowould rather + 从句从句would prefer to do.had better do.改错改错: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 .f. 3. 情态动词表示推测的用法情态动词表示推测的用法A. 对现在状态和动作的推测对现在状态和动作的推测高考题点击：高考题点击：1. Peter _ come with us tonight, but he isnt very sure yet. (N 1993) A. mustB. may C. canD. will2. Michael _ be a policeman, for he is much too short. (1994上海) A. needntB. cantC. shouldD. mayBBmust 加动词原形表示“必须做”；may 加动词原形表示“可能会做”；can 加动词原形表示“能够做”；can 表示“可能性”时只用在问句和否定句中。该句的关键在于“but he isnt sure yet”。 neednt 表示“不必”；cant 表示“肯定不”；后两个选项与句意差别太大。此句的关键在于 “for he is much too short”.3. Its nearly 7:00. Jack _ be here at any moment. (N 1995) A. mustB. needC. shouldD. can4. Johnny, you _ play with the knife, you _ hurt yourself. (N 1996) A. wont, cantB. mustnt, may C. shouldnt, mustD. cant, shouldCB must + be 表示“肯定会”；need + be 表示 “需要在”；should + 动词原形表示“非常有可能”；can 表示可能性只用在否定和疑问句中。前句表示“你不能玩刀”，此处的 “不能”并非表示“能力”，而是表示“允许”，所以只能用“mustnt”；后句表示“可能会伤着你自己”，故用 may。5. - Are you coming to Jeffs party? - Im not sure. I _ go to the concert instead. ( N 2000) A. mustB. wouldC. shouldD. might6. Mr. Bush is on time for everything. How _ it be that he was late for the opening ceremony? (2001上海春季) A. canB. shouldC. mayD. mustDA此句的关键在于“Im not sure”，既然不能肯定，只能是一种“可能性”。此句的意思为：“Bush 先生总是很守时，他怎么可能在出席开幕仪式时迟到呢？“ can 在否定句或疑问句中表示“可能性”。7. - Is John coming by train? - He should, but he _ not. He likes driving his car. (N 2002) A. mustB. canC. needD. may8. - I heard they went skiing in the mountains last winter. - It _ true because there was little snow there. (N 2002北京) A. may not beB. wont be C. couldnt beD. mustnt beDC此句的关键是“He likes driving his car.” can 和 may 都可用于否定句中，cant 表示“根本不可能”，语气很强；may not 表示“也许不可能”，语气较弱。 couldnt 的语气比 cant 弱。B. 对过去动作或状态的推测对过去动作或状态的推测1.Tom ought not to _ me your secret, but he meant no harm. (N1993) A. have told B. tell C. be tellingD. having told2. I told Sally how to get here, but perhaps I _ for her. (N 1994) A. had to write it outB. must have written it out C. should have written it outD. ought to write it outAC ought to 相当于 should；此句的关键是“He meant no harm”，显然指的是过去的事。 should have written 意指“本该写但实际上并没有写”。3. - There were already 5 people in the car but they managed to take me as well. - It _ a comfortable journey. (N 1995) A. cant beB. shouldnt be C. mustnt have beenD. couldnt have been4. Susan_ written a report like this. (1995上海) A. can haveB. mustnt have C. cant haveD. ought to not haveDC此句谈论的是过去的经历，故 A、B 不合题意；must 表示判断和推测只能用在肯定句中。该句的意思为 Susan 不可能写出这样的报告来。ought to have done 的否定式为 ought not to have done。5. Jack _ yet, otherwise he would have phoned me. (N 97) A. mustnt have arrivedB. shouldnt have arrived C. cant have arrivedD. neednt have arrived6. - I stayed at a hotel while in New York. - Oh, did you? You_ with Barbara. (N 1998) A. could have stayedB. could stay C. would stayD. must have stayedCA此句的关键是后半句，“otherwise he would have phoned me”，此处为省略了条件句的虚拟语气，表示“如果到了他会打电话给我的”，由此可见，他肯定没到。此句并不表示判断，而是一个虚拟语气。7. There was a lot of fun at yesterdays party. You _ come, but why didnt you? (1999上海) A. must have B. shouldC. need haveD. ought to have8. I was really anxious about you. You _ home without a word. (N 2001) A. mustnt leaveB. shouldnt have left C. couldnt have leftD. neednt leave9. Oh, Im not feeling well in the stomach, I _ so much fried chicken just now. (2002上海春季) A. shouldnt cutB. mustnt have eaten C. shouldnt have eatenD. mustnt eatDBC4. shall; should 的特殊用法的特殊用法 1. It has been announced that candidates _ remain in their seats until all the papers have been collected. (2002上海) A. canB. willC. mayD. shall2. Its nearly 7:00. Jack _ be here at any moment. (N 95) A. mustB. needC. shouldD. canDC该句的意思为：“通知说所有的考生必须坐在位置上直到考卷收完了才能离开。”考生坐在位置上不能用“能够、将要、可以”来表示。而 shall 在第二、三人称里面表示一种“命令、警告、承诺”等。3. - When can I come for the photos? I need them tomorrow afternoon. - They _ be ready by 12:00. (N 1998) A. canB. shouldC. mightD. need4. You cant imagine that a well-behaved gentleman _ be so rude to a lady. (2001上海) A. mightB. needC. shouldD. wouldBC此句应是店主对顾客的承诺。 should 与 how; why 等表示疑问或否定的词连用时，用来表示一种惊奇的心情，意思为“居然、竟然”5. 情态动词的应答情态动词的应答 1. - Shall I tell John about it? - No, you _. Ive told him already. (N 1994) A. needntB. wouldntC. mustntD. shouldnt2. - Could I call you by the first name? - Yes, you_. (1998上海) A. willB. couldC. mayD. mightAC此句的关键是“Ive told him already”，由此可见，你就不必再对他说了。在回答 “Could I ”这类婉客气的请求时，只能回答“Yes, you can 或 may”。不能用 could 或 might。3. - Will you stay for lunch? - Sorry, _. My brother is coming to see me. (N 1999) A. I mustnt B. I cantC. I needntD. I wont4. - Write to me when you get home. - _. (2001北京春季) A. I mustB. I shouldC. I willD. I canBC此句的关键是 “My brother is coming to see me.” 所以我不能在这儿吃饭。在回答对方的请求或命令时，应该用 “Yes, I will.”而不能使用 would 或 should。6. 情态动词的其它一些用法情态动词的其它一些用法1. I wonder how he _ that to the teacher. (1996上海) A. dare to say B. dare saying C. not dare say D. dared say2. The fire spread through the hotel very quickly but everyone _ get out. (N 1997) A. had toB. wouldC. was able toD. could3. When he was there, he _ go to that coffee shop at the corner after work every day. (1996上海) A. wouldB. shouldC. had betterD. mightDCA注意比较 dare 和 need 的两种词性的不同用法。注意比较 could 与 was able to 的用法区别。 would 在此处表示过去惯常的动作。1. The fire spread through the hotel very quickly, but everyone_get one.A. were able to B. wouldC. was able to D. could2. You_return the book now, you can keep it until next week if you like,A. cant B. mustntC. neednt D. may not3. When he was there, he_ go to that coffee shop at the corner after work every day.A. would B. should C. had better D. might4. -Could I use your bike?Yes, of course.you_.A. might B. will C. can D. shouldCCAC5. -Will you stay for lunch?-Sorry, _. My brother is coming to see me.A. I oughtnt to B. I cantC. I neednt D. I shouldnt6. -_I invite Jcak to the party?-Yes, itll be nice if you_.A. Will; may B. Shall; willC. Shall;shall D. Will; will7. -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 beC. mustnt have been D. couldnt have beenBBD8. We_last night, but we went to the concert instead.A. must have studied B. might studyC. should have studied D. would study9. There was plenty of time. She_.A. mustnt have hurried B. couldnt have hurriedC. mustnt hurry D. neednt have hurried10. Yesterday, Jane walked away from the discussion. Otherwise. She_something she would regret later.A. had said B. saidC. might say D. might have said.CDD11. -Did you scold him for his mistake?-Yes, but_it.A. Id rather not doB. Id better not doC. Id better not have doneD. Id rather have not doneD