情态动词的用法归纳稿三.doc

M4U2 Grammar :Modal Verbs 情态动词情态动词，在英文中主要用来表示说话人的看法、态度等。从用法上来说，它有这样几个特点：1）各个情态动词自身都有一定的词义。2）情态动词不能在句中独立担当谓语。3）情态动词在句中不受任何人称,性,数变化的影响。4) 情态动词后接的不定式（除ought外）都不带to ，即接动词原形。一 can和could情态动词用法例句can/could(1)表示能力1“I dont think Mike can type.” “Yes, he can.”2I can speak fluent English now , but I couldnt last year.(2)表示请求和允许。表示请求，口语中常用could代替can，使语气更委婉。回答时常用may/can1 You cant smoke here.2 Could I use your bike? 3 -Could /Might I use your bike tomorrow morning?-Yes, you can/may.4 In soccer, you cant touch the ball with your hands.5 Can /Could I turn the air conditioner on?6 Could you have her call me back when she gets home, please?7. I wonder if I could just ask you to sign this.(3)在肯定句中，表示“有时可能”。表示客观可能性，并不涉及具体某事会发生，常用来说明人或事物的特征。要表达具体某事实际发生的可能性时，不用can，需用could，may，might。1 Even an experienced teacher can make mistakes. （客观可能性）2 It can be warm even in winter. （客观可能性）3 Accidents can happen on such rainy days. （客观可能性）4 I may stay at home this weekend.（实际可能性）5 Peter might come to join us, but he is not sure yet.(实际可能性) 6. We may go camping next Sunday. .(实际可能性) 7. He can be very forgetful sometimes. （客观可能性）8. It will be sunny in the daytime ,but it could rain tonight.(实际可能性)(4)表示猜测、惊异、怀疑、不肯定等态度，主要用在否定句、疑问句和感叹句中。Can/cant do (现在)can/cant/could/couldnt have done (过去)1.The story cant be true.2.How can/could you be so careless!3.Look, his coat is still here, so he cant/couldnt have left.4.My dictionary is missing. Who can/could have taken it away?5.Mr. Bush is on time for everything. How can it be that he was late for the opening ceremony?6.Can this be an excuse for not giving them help?7. It cant be easy caring for a man and a child who are not your own.(5)表示命令“请做（你）得”1.Ill do the cooking, and you can do the washing(较礼貌)特别说明：(1)can和be able to辨析 can(could)和be able to都可以表示能力，意思上没有区别。但can只有现在式和过去式，而be able to则有更多的形式。如：She could/was able to sing like an angel when she was a child.(一般能力)Ive always wanted to able to speak fluent English.Those bags look really heavy, are you sure youll be able to carry them on your own?但是，表示在过去某时的某一场合经过一番努力，终于做成了某事，通常不用could，而用was/were able to来表示。这时，was/were able to相当于managed to do或succeed in doing。如：After the accident it was a long time before she was able to walk again.The fire was very big, but most people were able to escape from the building.有时以非生物做主语时，不能用be able toI dont care for money, because money cant buy me happiness.我不在乎钱，因为钱买不到幸福(2) 惯用形式“cannot too/enough”表示“无论怎么也不（过分）”。如：You cannot be too careful.你越小心越好。You cant remember enough English words. 惯用形式“cannot but+ 不定式（不带to）/cant help doing/cant help but do”表示“不得不，只好”。如：I cannot but admire her determination.我不得不钦佩你的决心。I cant help but agree with her.惯用形式asas one can=asas possible(3) could用来表示请求时，语气委婉，主要用于疑问句，不能用于肯定句，答语应用can（即：could不能用于现在时态的简略答语中）。如：Could I use your dictionary?Yes, you can.(否定回答可用：No, Im afraid not.)(4) see, hear, feel ,smell, taste等感官动词通常不用进行时，但和can连用时与进行时一样表“正在看，正在听”I can smell something burning . 二may和 might情态动词用法例句may/might(1)表示请求、允许。在表示请求时，might比may语气更委婉些。肯定回答用can/may否定回答一般用mustnt表示“禁止、阻止”或may/can not（不可以），但也可用had better not等语气较委婉。在日常用语中，用Can I征询对方意见更为常见。1 The manager told me that I might have a vacation.2 -May I smoke here?-Yes, you may/can.(对晚辈)- No, you mustnt (或No, youd better not.)3 -May/Might I come in and wait?-Certainly/Why not/Sure/Yes, please/Of course(多)-No, Im sorry/Im afraid you cant/please dont.4. I wonder if I might speak to your son.(2)表示可能性的推测，通常用在肯定句和否定句中，含有“或许”“大概”“可能”之意；用might则语气显得更加不肯定。may/might not“可能不”1 It may rain this afternoon.2 She might come to join us this afternoon.3. He may not like this noisy place.4. Can that be true?(不用May)（3）may用于祈使句表示祝愿1 May you succeed.2 May you return in safety!愿你平安归来3 May we never forget each other!愿彼此永不相忘4 May she rest in peace.愿她安息。5 Long may he live! 愿他能持续住下去。（4）惯用句式：“may/might well+ 动词原形”，表示有充分的理由，意为“完全能，很可能”，=be very likely to“may /might(just)as well(not)+do/have done”表示建议，意为“最好，满可以，倒不如，不妨”，相当于“had better或there is no reason to do anything else.1 You may well say so.你完全有理由这么说2 There may well be a real problem here.3 There is nothing to do, so I may as well go to bed.4 You may as well tell us now, as well find it out sooner or later.5 - I went with them to see the film, but it was boring.-You might as well have stayed at home with me watching TV.（5）表示让步“可能、或许”1. She may be beautiful, but she is cool.2. Whatever she may say, I dont believe her.3. Although this may sound like a simple task, great care is needed.（6）表示目的“以便”1. He works hard so that he may get good grades.三must和have to情态动词用法例句must（1）表示“必须，应该”之意，语气强烈。其否定形式mustnt表示“不准，不应该，禁止”等意。在回答带有must的问句时，否定回答常用neednt或dont have to，表示“不必”，而不用mustnt1 You must come to school on time.2 Everybody must obey the law.3 You mustnt drive so fast in the street.4. Must I come back before ten?Yes，you must.(No, you neednt/dont have to)（2）表示有把握的推测，意为“一定、准是、相必”，只用于肯定句中1 It must be my mother.2 You must be hungry after a walk.3There must be a hole in the wall.（3）表示必然“一定”1.Man must die.人都会死的。（4）表示“偏要，坚持要”1.Must you play the piano at this time?2.-How old are you ,madam? -If you must know, Im twice my sons age.have to(1)“必须，不得不”，意义与must相近。但must表示的是说话人的主观看法，而have to则往往强调客观需要。1 The film is not interesting. I really must go now.2 Im afraid I must be leaving.3 I have to go now, because my mother is in hospital.(2)must只有一种形式，即现在式与过去式都是一种形式，而have to则涉及各种人称、时态等方面的变化形式。1I had to work hard when I was your age.2I will have to learn how to use a computer.(3)两者的否定意义不同，mustnt表示“禁止，不许”，dont have to表示不必。1 You mustnt go there.2 You dont have to go there.四shall和should情态动词用法例句shall用于第一、三人称构成的疑问句，表示征求对方意见或请求指示1 Shall I open the window?2 Shall he come in ,sir?3 What shall I get for dinner?4 Shall we say 6 oclock, then?（2）用于第二、三人称陈述句中，表示说话人给对方的命令、警告、允诺、威胁、规定等。1 I promise you shall see her again before long(允诺)2 He shall be sorry for it one day, I tell you. （警告）3 You shall do as I say. (命令)4 The fine shall be paid in cash.(规定)5 All the candidates shall remain in their seats until all the papers have been collected.(规定) （3）表示说话者的决心或强烈的意志等“必定要”1. I shall never forget that bad treatment.2. I shant speak with her.我绝不跟她说话了。should(1)表示劝告或建议，意为“应该”1 What should I do?2 You should follow the doctors advice.(2)表示按照常规有一定依据的推测，。意为“想必，大概，或许，按道理说”1 Its seven . Jack should be here at any moment.2 -When can I come for the photos? I need them tomorrow.-They should be ready by 12:00. 3 It should be a nice day tomorrow.4 He should be around sixty years old.(3)有时与I连用，表示委婉的语气1 You are mistaken, I should say.要我说，你是搞错了。2 I should advise you not to do so.我倒是劝你别这么做。3 I should be grateful if you could provide me with information.(4) 用于疑问句或感叹句中Why/How should表示说话人对某事不能理解，感到意外、惊异“竟会” 疑问句，无需回答;Its adj.(surprising/strange) thatshould1 Why should you be so late today?2 Dont ask me. How should I know?3 Its surprising that he should be so rude.4 Why should anyone want to marry Tony?（5）用在if引导的条件句中，表示一件事听起来可能性很小，但也不是完全不可能，相当于“万一”的意思。从句谓语用should+动词原形构成，主句都一定用虚拟语气4 Ask Tom to ring me up if you should see him. (你万一见到汤姆，请让他给我打个电话)5 Should I be free tomorrow, Ill come. (万一我明天有时间，我就过来)6 If things should change suddenly, please let me know. (万一情况突变，请通知我)ought toShould表主观看法 ought to语气中含有 “按道理应该”主要反映客观事实或涉及法律义务和规定1.You should help them with their work.2.You are his father. You ought to get him to receive good education.五will和would情态动词用法例句will/would(1)用于表示意志或意愿。will指现在，would指过去。1 I will go all out.2 I shall be glad if you will help me.3 His father was angry because he would not obey him.4. I wont listen to your nonsense.5. No matter what I said, he wouldnt listen to me.(2) 与第二人称连用，表示请求、建议等，用would比用will委婉、客气。1 Will /Would you please take a message for him?2 Wont you come in and have a cold drink?3 Go and get some water, will you?(3)表示习惯或倾向，意为“总是，惯于”。will至现在，would指过去。1 Oil and water will not mix.油和水总是互不相溶2 Dont get ink on your shirt. It wont wash.3 He would sit there for hours , doing nothing at all.4 Boys will be boys.(4)表示推测，意为“很可能，大概”。will表示推测比should把握大，比must把握小。1 These things will happen.2 It would be about ten oclock when he left home.(5)表示功能，意为“能，行”。惯用形式：will do/would do表示“解决问题”、“就行”。常与无生物的主语连用。1 That will be all right.2 Either pen will do.3 It would not do to work too late.（工作太晚不行）4 This hall will seat five hundred people.特别说明：would与used to辨析would表示过去反复出现的动作，但不表示过去存在的状态，同现在没有联系。不能说：“she would be a quiet girl.”used to表过去的动作或状态。着眼于过去和现在的对比，隐含现在已不存在He used to be a naughty boy and cause trouble.Would可以表示不规则的习惯，长与often,sometimes,always,for hours,of a day连用。used to则表示较规律的习惯。would主语的关心，感慨等主观因素较强时使用。“Ill leave this job for a better one.”he would say when he was scolded by his boss.would常与often, sometimes, for hours等表示时间的副词连用。 1.He used to be a naughty boy and cause trouble. 2.Now he has not enough money to spend on books as she used to. 3.Sometimes she would take a walk in the neighboring woods. 4.There used to be a small village there.六need和dare情态动词用法例句need(1)用于表示“需要，必要”之意。做情态动词时，没有人称和数的变化，主要用于否定句和疑问句和条件状语从句中。1Need we leave soon? Yes, you must.(No, you neednt)2You neednt come tonight since you are not feeling well(2)做实义动词时，其变化与一般的实义动词相同，后接带to的不定式（need doing = need to be done ）肯定式用needs/needed/need,疑问式用do、does、did提问，否定式要在前面加dont、doesnt、didnt1.I think you need to do it again.2.We need more time.3.-Does he need to do it again? -No, he doesnt.4.The floor needs washing/to be washed.dare(1)用于表示“敢于”之意。做情态动词，没有人称和数的变化，主要用于否定句、疑问句和条件状语从句中1Dare you tell her the truth? Yes, I dare. /No, I darent.2.How dare you accuse me of lying!3.I dare say hell come again. 我想(2)用作实义动词时，其变化与一般的实义动词相同。在肯定句中，dare后接带to的不定式；疑问，否定句中，dare后既可接带to的不定式，也可接不带to的不定式。过去时dared1 We must dare to think, to speak and to act.2 He doesnt dare (to) speak before a big audience.3 Dont you dare (to) touch it?七ought的用法：情态动词用法例句ought to do表示“应该”之意1 You ought to take care of him.2 Ought I go now?Yes, you ought to. /No, you oughtnt to.表示推测。注意与must表示推测是的区别1 He must be home by now. (断定他已到家)2 He ought to be home by now. (不十分肯定)3 This is where the oil must be. (比较直率)4 This is where the oil ought to be. (比较含蓄)说明：should与ought to 表示“应该”时的区别should 表示自己的主观看法，而ought to的语气中，含有“按道理应该”之意。若要反映客观情况或涉及法律义务和规定，一般用ought to。如： You should help them with their work. You are his father. You ought to get him to receive good education.二 情态动词难点突破1.表示推测：对现在：情态动词+do/be doing 对过去：情态动词+完成时 (have done)(1) must have done一定已经（对过去语气最强的推测）must do/must be doing一定在做 (2) may/might have done可能已经做 may do/may be doing可能在做 may/might not have done可能没有已经做（3） cant/ couldnt have done不可能已经做can/could have done可能已经做cant do/can do不可能做注意：当情态动词表推测时的反意疑问句的用法：He must be at home, isnt he?He must have gone home, hasnt he?He must have watered the plants yesterday, didnt he?It cant have rained yesterday, did it?He couldnt have been to Greek, has he?He cant be a lawyer, is he?2“情态动词+have done”用法情态动词+have done用法例句must have done 表示主观上对过去已经发生的行为进行推测，意为“想必，准是，一定做了某事”1 She must have gone through a lot.2 He must have visited the White House during his stay in the United States.may/might have done表示对过去已发生行为的推测，意为“也许/或许已经（没有）“。一般用于肯定句或否定句中，不用于疑问句。用might则表示语气更加不肯定。1 You may have learnt the news.2 He may not have heard his name called.3 Sorry Im late. I might have turned off the alarm clock and gone back to sleep again.canhave donecannot have done表示对过去发生的行为的怀疑和不肯定，通常用在否定句和疑问句中。（can换成could时语气委婉）1 Where can she have gone?2 Could he have done such a foolish thing?3 The boy cant have finished reading the book so soon because it is difficult even to an adult.could have done可用于肯定句中，表示“可能已经”之意，此外，还可以表示过去能做而没做的事，有一种对过去为付诸实施的事情的惋惜。1 He could have killed himself driving at a dangerous speed.2 You could have been more considerate.3 You could have done better, but you were too careless.might have done表示“本来可能，但实际上没有发生的事情”。另外，还可以表示“本来应该或可以做某事”之意，含有轻微的责备语气。1 You should not swim in that sea. You might have been eaten by a shark.2 He might have given him more help, thought he was busy.should/ought to have donebe supposed to have done用于肯定句时，表示本该做某事，而实际上未做；用于否定句时，则表示不该做的事反而做了。1 He should have known that the police would never allow this sort of thing.2 You shouldnt have done it so carelessly.3 You ought to have returned the book earlier.4 You ought not to have refused his offer.neednt have done表示做了本来不必去做的事。注意：didnt need to do表示“没必要做而实际上也没有做某事”1 You neednt have watered the plants, for it is going to rain.2 I didnt need to buy the dictionary. I had a copy at home.had better have done用于事后的建议，含轻微责备的口吻，意为“当时最好做了某事”，其否定式had better not have done表示相反的含义。1 You had better have started earlier.2 You had better not have scolded her.would rather have done表示“当时宁愿做了某事”，其否定式would rather not have done表示相反的含义，两者都表示“后悔”之意。1I would rather have taken his advice.2I would rather not have told him the truth.巩固练习一：情态动词+have1.We all felt worried about you. You _(leave) without a word.2.I didnt tell him the date of the meeting, but I _3.I cant find his school bag, so he _(go) home.4.-Where is Jeff? -He _(go) to work, but Im not sure.5.Although they _(not make) any new discoveries, but they have done their best.6.I saw him in the street just now, so he _(go) abroad.7.I cant find him anywhere. _he_(go) home?8.I cant find my dictionary. Who _(take) it away?9.You_(give) him more help even if you were busy.10.-Where did you stay when you were in NewYork?-I stayed in the hotel.-Oh, you_(stay) with Babara because she has a large house.11.-Did you manage to repair the machine last night?-No, and the whole night was wasted.-Oh, you _(turn) to my brother for help. He is quite an expert in it.12. -I sent her an email about the changes of the plan this morning. -Oh, you _(do) it. I had already called her about it.13.- My father made a call to Mr. Smith just now. -On, he _(do) so. Mr Smith is coming here tomorrow.巩固练习二1.-Dont forget to bring my new books tomorrow afternoon. -No, I_.A.dontB.cantC.wontD.couldnt2.-I hear youve got a set of American coins._I have a look? -Yes, certainly.A.DoB.MayC.ShallD.Should3.He seldom listens to others. He _be responsible for what he has done.A.shallB.willC.canD.would4.-May I leave the office before 5 oclock in the afternoon? -No, Im afraid you_.A.needntB.wontC.cantD.might not5.Mr Brown is on time for everything. How_it be that he was late for the opening ceremony?A.canB.shouldC.mayD.must6.The traffic light is red, so I _stop.A.mustB.have toC.canD.mustnt7.I was really anxious about you. You_home without a word.A.mustnt leaveB.shouldnt have leftC.couldnt have leftD.neednt leave8.Children _in public very often.A.should be praisedB.shouldnt have praisedC.shouldnt be praised D.shouldnt have been praised9.Lets clean the classroom,_?A.wont youB.shall weC.do weD.will not we10. Tom_show his exam results to his parents.A.dare notB.daredC.dare toD.dares not to11.I dont think he_a new bike.A.need to buyB.needs buyC.needD.need buy12.-Nacy _the letter from her mother. -No, she cant have. The postman hasnt come yet.A.can receiveB.can have receivedC.must have receivedD.must receive13.She _the film. She knows nothing about it.A.cant seeB.cant have seenC. must seeD.mustnt have seen14.They must have gone there the day before yesterday,_?A.mustnt theyB.didnt theyC.mustnt have theyD.cannot have15.-I didnt see her yesterday. -Oh, but you_.A.must haveB.ought toC.should haveD.cannot have16.-Must I take a bus? -No, you_. You can walk from here.A.must notB.dontC.dont have toD.had better not to17.-Will you stay for lunch? -Sorry, I_. My brother is coming.A.mustntB.cantC.needntD.wont18.Oh, Jenny, youve broken another glass. You ought _when you washed it.A.be carefulB.to careC.have caredD.to have been careful19.I _often go fishing when I lived in the countryside.A.shouldB.wouldC.couldD.might20.He _rather stay at home than go to the cinema with you.A.shouldB.mightC. wouldD.had better21.Its high time we_to the theatre.A.will goB.shall goC.are goingD.went22.-Could I use your telephone? -Yes, of course you_.A.couldB.willC.canD.might23.I wish you_go with me tomorrow