高考语法6—情态动词与虚拟语气.doc

.高考语法专题复习之六第六讲情态动词与虚拟语气【知识梳理】高考常考考点：1. 情态动词本身所表达的意义，如表示禁止、命令、威胁、许诺等意义；may, might, need, should等的用法。2. “情态动词+have done”表示推测。3. 情态动词后面省略形式的用法区别，如：could (do），could have (done)的区别。4. 虚拟语气中的含蓄条件句以及宾语从句。5. 判断陈述语气与虚拟语气。一、情态动词(一) 情态动词的基本用法1. can be able to couldcan和be able to都表示能力，意思上没多大区别。但can只有现在和过去时，而be able to则有更多的形式。但当成功地完成某一具体动作时，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，表示经过一番努力，终于能够完成某事。如：The wounded man still was able to get to the village and was saved in the end.can和could: can和could都可以表示能力、技能、许可、建议或请求和可能性。但比较委婉客气地提出问题或陈述看法，一般用could，回答时则用can。如：Could you help me carry the bag?Can I help you?2. may/mightmay/might表示可能，但may比might可能性大。如：Why isnt he in class?He may be sick.(生病的可能性较大)He might be sick.(生病的可能性较小)may/might表示允许，may用于现在时或将来时，might常用在间接引语中表过去时，但might也可用于现在时间，表示比较委婉的语气，回答用may。如：He says we may leave.He said we might leave.may / might 表示建议或请求，但might比may 更客气，意思更肯定而无过去时态的含义。如：-May / Might I use your bike? -Yes, you can / may. /-No, you mustnt3. must have tomust表示必须，应该，强调主观意愿，没有时态变化。must表示肯定的推测。如：The light is still on, so he must be at home.mustnt 表示禁止做某事。如：have to表示必须、不得不，是由于某种外界（客观）原因而必须，不得不做某事，也可表示经常的或习惯性的事必须做。have to的否定形式表示不必。have to可用于多种时态中。如：You will have to clean your own boots when you join the army.I have to be at my office every evening.4. should / ought toshould和ought to表示应当、应该，前者比后者语气轻。如：You should / ought to work hard.Since she is not here, he should / ought to be in the classroom.should/ought to的否定形式表示禁止之意。如：Children shouldnt smoke.should可表示陈述意见，推出建议或请求；而ought to可以表示劝告之意。如：You ought to respect your parents.He suggested that they should leave at once.5. will / wouldwill 用于各种人称表示意志、意愿或决心等，否定式wont + 动词。如：I will tell you all about it./ Tom wont do such a thing.will用于疑问句中，常用在第二称时表示说话人向对方提出请求或询问如：Will you tell her the news when you see her?will 表示习惯性的动作，有总是、惯于的含义。如：Fish will die out of water.would 表示客气的请求、建议或意愿。如：Would you please be quiet?Would you like coffee?would 表示过去反复发生的动作。如：When I passed my school，I would see my teachers who taught me 5 years ago.6. need: 作必要讲，既可作情态动词，也可作实义动词。作实义动词时后面的动词不定式要带to，其变化与一般动词相同。如：I need to think it over.Need you go now? Yes, I must./No, I neednt 7. dare: 表示敢的意思。作为情态动词时，主要用在疑问句和否定句中。dare若作实义动词，后面可带to的不定式，此时to也可以省略。dare与need的用法相似。如：How dare you say that?She doesnt date(to)ask her father.8. used to: 表示过去常常发生的动作或存在的习惯，但现在已不复存在了。如：He used to smoke.9. shallshall作为情态动词用于第二、三人称，表示说话人的意愿，有命令、警告、威胁、强制和允许等意思。如：We/You shall do as our teacher says.在疑问句中，shall用于征求对方的意见或请求指示，常用于第一、第三人称。如：Shall he go out for a walk?二、虚拟语气：用于条件状语从句中1. 表示与现在事实相反的假设条件状语从句中的谓语动词：过去式（be动词的过去式用were），主句中的谓语动词:would/should/could/ might + 动词原形。如：If I were a boy, I would join the army.If she had time, she should go with you.2表示与过去的事实相反条件状语从句中的谓语动词：过去完成时，主句中的谓语动词：would/should/ might / could + have +过去分词。如：If he had taken my advice, he would have succeeded in the competition.3 表示与将来事实相反条件状语从句中的谓语动词：一般过去时或should(were to) + 动词原形，主句中的谓语动词则用would / should/could might + 动词原形。如；If it were to rain tomorrow, the football match would be put off.4 错综条件句：当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，动词的形式要根据它所表示的时间作相应调整。如：If they had worked hard, they would be very tired.(从句说的是过去，主句指的是现在)5. 虚拟语气的省略：有时可省略if,句子则变成下列形式：Were / Had / Should +主语+。如：Were I a boy, I would join the army.Had he taken my advice, he would have succeeded.Were it not for the expense, I would go to Britain.【疑难点拨】一、 情态动词表示推测或判断的用法1. 表肯定推测：1）对现在和未来的推测：must /may / might /could/should+动词原形2）对过去的推测must /may / might /could/should +have done2表否定推测：1）对现在和未来的推测：cant +动词原形2）对过去的推测cant +have donecant只用于否定句、疑问名（could可用于肯定句。例如：It must have rained last night.She may not be at home. = It is possible that she is not at home.She cant be at home. = It is impossible that she is at home.They should be there right now.二、 情态动词在虚拟语气中的用法情态动词用于虚拟语气中表示责备的感情色彩，用法如下：1. should have done表示本来应该做某事而实际上未做，而shouldnt have done则表示本不应该做某事而实际上做了。如：You should have told me about it earlier.You shouldnt have said such words to your parents.2. ought to have done 也表示本应该.，而ought not to have done则意为本不应该.。如：You ought to have told me about it earlier.You ought not to have said such words to your parents.3. neednt have done 表示本不必做某事而实际做了。如：You neednt have walked so quickly since time was enough.4. could have done 表示本来能.而事实上未做到。如：I could have come on time, but my car broke on the way.三、虚拟语气用于名词性从句1. 虚拟语气在宾语从句中的运用。wish + 宾语从句表示不能实现的愿望，译为要是.就好了等。表示现在不能实现的愿望，从句中的谓语动词用一般过去时；表示将来不能实现的愿望，从句中的谓语动词用would/could + 动词原形；表示过去不能实现的愿望，从句中的谓语动词用had + 过去分词或could(should) + have + 过去分词。如：I wish it were spring all the year round.I wish I had known the answer.I wish I could fly like a bird.在表示建议、要求、命令等的动词suggest，advise，propose，demand，require，insist，request，command，order等后的宾语从句中，谓语动词用should + 动词原形或是动词原形。如：She suggested we (should) leave here at once.The doctor ordered she should be operated on.2. 虚拟语气在同位语从句和表语从句中的运用。作表示建议、要求、命令等的名词advise，idea，order，demand，plan，proposal，suggestion，request等的表语从句和同位语从句，从句中的谓语动词用（should） + 动词原形。如：His suggestion that we (should) go to Shanghai is wonderful.My idea is that they (should) pay 100 dollars.3. 虚拟语气在主语从句中的运用。在主语从句中，谓语动词的虚拟语气用should + 动词原形的结构，表示惊奇、不相信、理应如此等。如：It is necessary(important, natural, strange, etc.)that we should clean the room every day.It was a pity (a shame, no wonder, etc.)that you should be so careless.It will be desired(suggested, decided, ordered, requested, proposed, etc.)that she should finish her homework this afternoon.注意：这种从句表示的是事实。如果说人对这种事实表现出惊奇的情感，就可用虚拟语气。反之，如果不表示惊奇等情感，that从句也可用陈述句语气。如：It is a pity that you cant swim.四、虚拟语气在其他场合的运用1 虚拟语气在as if/as though、even if/even though等引导的表语从句或状语从句中，如果从句表示的动作发生在过去，用过去完成时；指现在状况，则用一般过去时；指将来状况则用过去将来时。如：He did it as if he had been an expert.Even if she were here, she could not solve the problem.2 虚拟语气用于定语从句中。这种从句常用于句型It is (high)time (that) . 中，定语从句的谓语动词用一般过去时(be用were)或should + 动词原形，意思是(现在)该.。如：Its time that I picked up my daughter.Its high time we were going.3 虚拟语气用在if only引导的感叹句中。如：If only I were a bird./If only I had taken his advice.4 虚拟语气在一些简单句中的运用。情态动词的过去式用于现在时态时，表示说话人谦虚、客气、有礼貌或语气委婉，常出现在日常会话中。如：It would be better for you not to stay up too late.Would you be kind enough to close the door?用于一些习惯表达法中。如：Would you like a cup of tea?I would rather not tell you. 5. without, but, but for, otherwise引起的短语或句子常暗含着含蓄条件。Without you, I would never know him. But for your cooperation, we wouldnt have done the work so well. = If it were not for your cooperation, we we wouldnt have done the work so well.注： without / but for = If it werent not for/ If it hadnt been for , sb .I would be most glad to help you, but I am busy now.I am busy now, otherwise I would do you the favor! 【思维拓展】 1. （2007，湖南，24）The biggest problem for most plants, which _ just get up and run away when threatened, is that animals like to eat them.AshantBcantCneednt Dmustnt答案 B解析 句意：对大多数受到威胁时又不能起身逃跑的植物来说，最大的问题是动物喜欢吃他们。A shant 将不；B cant 不能C、D项不合题义。故选B。点拨 考生应掌握情态动词的基本用法并根据上下文作出选择。变式 You get up and run away when asked to stop by police, or you will be shot at.AshantBcantCneednt Dmustntshant 不允许/必须不（表说话人的意愿）；mustnt一定不能/禁止（表主语的意愿）。故选A。2. （2007，福建，27）If it were not for the fact that she _ sing, I would invite her to the party.A. couldntB. shouldntC. cantD. might not 答案 C解析 句意：如果不是她真不会唱歌，我会邀请她去参加晚会。that引导的同位语从句说明fact的内容，用陈述语气。故选C。点拨 考生应能辨别陈述语气与虚拟语气。变式 If she _ sing, I would invite her to the party.A. couldB. shouldC. canD. might 根据句意，if从句为与现在事实相反的虚拟条件句。故选A。3. I was really worried about her. She _home without saying a word.A.mustnt have leftB.shouldnt have leftC.couldnt have leftD.neednt have left答案 B 解析 本题考查的是情态动词在虚拟语气中的用法。题目给出的条件是我确实非常担心你，因此后面可知应是责备you不应该没说一句话就离开了。点拨 考生应掌握情态动词在虚拟语气中的用法。变式 I was really worried about her. She _ me when she left home.A.must have toldB.should have toldC.could have toldD.need to have told根据句意可知：她应该告诉我（实际没告诉我），用虚拟语气。故选B。4. Are you coming to my party?Im not sure. I _ go to the cenema instead.A. mustB.wouldC.shouldD.might答案 D 解析 由题目中Im not sure,表明我可能去Jeffs party，也可能去音乐会，故用might。点拨 考生应掌握情态动词的基本用法。变式 The outbreak of bird flu tells us that a sound public health system be built up and strengthened in our country.A. mustB.mayC.shouldD.might根据句意选should(应该)。故选C。5. Will you stay for dinner?Sorry, _. My mother is coming to see me.A.I mustntB.I cantC.I needntD.I wont答案 B 解析 用will来向第二人称提问的疑问结构，是表示一种请求和意愿，是用疑问的形式来表达较为婉转的祈使语气，意思是请你.，好吗，对于这种问句的肯定回答是：Sure! Gertainly! Yes, of course. Id be glad to 等；否定回答通常是：Im sorry, I cant. No, Im afraid I cant. Im sorry, but . Id like to, but .等。点拨 考生应掌握用情态动词表示请求的英语口语，注意情态动词表客气的用法及其在一般疑问句中的问与答。变式 -Must I stay for dinner?-No, you _. If you have finish your work, you may leave now.A. mustntB. cantC. needntD. wontMust?的否定回答用No,neednt。故选C。【小题训练】1. Isnt that Anns husband over there?No, it be him, Im sure he doesnt wear glasses.A. cantB. must notC. wontD. may not2. You be tiredyouve only been working for an hour.A. must notB. wontC. cantD. may not3. I often see lights in that empty house. Do you think I report it to the police？A. shouldB. shallC. mayD. can4. When a pencil is partly in a glass of water, it looks as if it _.A. breaksB. has brokenC. were brokenD. had been broken 5. I didnt see your sister at the meeting. If she _, she would have met my brother.A. has comeB. did comeC. cameD. had come6. If he _, he _that food.Luckily he was sent to the hospital immediately. A. was warned; would not takeB. had been warned; would not have takenC. would be warned; had not takenD. would have been warned; had not taken7. Mr.White at 8:30 for the meeting, but he didnt show up.A. should arriveB. should be arrivingC. should have arrivedD. should have had arrived8. Ill tell Mary about her new job tomorrow.You her last week.A. ought to tellB. would have told C. must tellD. should have told9. Lets go and have a good drink tonight. Have you got the first prize in the competition?A. What for?B. Thanks a lot. C. Yes, Id like to.D. Why not?10. English is a language that many people around the world_ not speak perfectly but_ at least understand.A. may; can B. would; might C. will; mustD. could; might11.Didnt they come to the party last week?Yes. They didnt want to come with us at first, but then we _ persuade them.A. wouldB. could C. were able toD. had to12.I promise her daughter _ get a nice present on her birthday.Will it be a big surprise to her?A. shouldB. mustC. wouldD. shall13. All of us had a good time in the picnic last Sunday. Pity you werent there.I really _come but I was looking after my mother in hospital.A. mustB. ought toC. need haveD. should have14. Did you scold him for his carelessness?Yes, but _ it.A. I would rather not doB. Id rather not have done C. I shouldnt doD. Id better not do15. Just as we were sitting down to have dinner, the telephone _ ring.A. mustB. couldC. mightD. need16. Would you like to stay for another two days?Sorry, I _. One of my best friends is coming to see me.A. mustntB. cantC. needntD. wont17. Where is Johnson? I cant find him anywhere.He _ letters upstairs.A. might have written B. must have written C. must be writing D. must write18. Mrs Smith, I will fetch ten chairs for the meeting.You _fetch ten; six will do.A. may not B. mustnt C. needntD. cant19. You _ pay too much attention to your reading skill, as it is so important.A. cantB. shouldC. mustD. neednt20. Can you come to attend our party tonight?Sorry, but I do wish I _.A. hadB. canC. willD. could21. It is necessary that people both young and old in China _some English to be prepared for the Olympic Games to be held in Beijing in 2008.A. learnB. will learnC. must learnD. have learned22. If he his legs in the last training, he the coming World Cup, which he has been longing to compete in.A. hadnt hurt; would join inB. hadnt hurt; would have taken part inC. didnt hurt; would go in forD. didnt hurt; would have taken part in23. I was caught in a traffic jam for over an hour, otherwise I _you waiting for such a long time.A. will not keepB. have not keptC. had not keptD. would not have kept24. Though the girl had been suffering from the blood disease, she acted as if nothing _ to her while facing her friends and relations.A. happenedB. would happenC. was happenedD. had happened25. Its high time that we students _ even harder at our lessons as the national entrance examination is coming nearer.A. workB. will workC. workedD. have to work26. _him not to do so, he wouldnt havemade such a serious mistake.A. Did I persuadeB. If I persuadeC. If I should persuadeD. Had I persuade27. His suggestion that you _once more sounds reasonable.A. tryB. triedC. must tryD. can try28. Do you mind if we set out earlier tomorrow morning?Well, Id rather you_.A. dontB. didntC. wont D. wouldnt29. I _ to your birthday party last Sunday. Unfortunately, you were out on business.A. had comeB. came C. would comeD. would have come30. Is John coming by train?He should，but he _ not.He likes driving his car.A.must B.can C.needD.may31.The room is so dirty. _ we clean it?Of course.A.WillB.ShallC.WouldD.Do32. My English-Chinese dictionary has disappeared. Who _ have taken it? A.shouldB.mustC.couldD.would33. I heard they went skiing in the mountains last winter.It _ true because there was little snow there.A. may not beB. wont be C. couldnt be D. mustnt be34. It has been announced that candidates _ remain in their seats until all the papers have been collected.A. canB. willC. mayD. shall35. Did the train arrive in time?No.It _two hours ago.A.must have arrive B.ought to have arrivedC.must arrive D.ought to arrive36. Look at the trouble I am in! If only I _ your advice.A. followedB. would followC. had followedD. should follow37. It is hard for me to imagine what I would be doing today if I _ in love，at the age of seven，with the Melinda Cox Library in my hometown.A. wouldnt have fallenB. had not fallenC. should fall D. were to fall38. She insisted that she _ ill of him behind him，but he didnt believe it.A. hadnt spokenB. shouldnt speakC. wouldnt speakD. not speak39. It is high time the child _ to the hospital.A. is sent B. would be sentC. be sent D. were sent40. If it _ so hard，wed go to town.A. isnt rainingB. werent rainingC. doesnt rainD. has rain解析1. 答案A 本题考查情态动词表推测。问：那边的难道不是Ann的丈夫吗？答：不是。不可能是他，我确信他不戴眼镜。2.答案C 本题考查情态动词。句中破折号后的内容对前一句进行解释说明：你只工作了一个小时，所以你不可能累的。表否定推测时用cant。A项表禁止（不许），B项表未来，D项表不允许。均不可用，故选C。3. 答案A 本题考情态动词。在空房子里看到灯光，是一件奇怪而令人生疑的事，故问：你是否认为我应当把这事儿报告给警察？应用A。4. 答案C 本题考查的是as if 引导的让步状语从句中的语气问题，as if引导的状语从句如果与事实一致，不用虚拟语气，如果与事实相反，应用虚拟语气。题中当铅笔的一部分浸在水中，铅笔看上去好像断了。而实际上铅笔并未断，与事实相反，前半部分陈述是一般现在时，因而本句是对一般现在时的虚拟，用were broken。5. 答案D 本题考查的是if条件句中的虚拟语气。题意是：我在会议上没看到你姐姐，故你姐姐没来。因此如果她来了与事实相反，前面一句交代了虚拟语气的时态是一般过去时的虚拟，所以if从句中用had+过去分词。6. 答案B 本题考查的是条件状语从句与主句表示与事实相反时虚拟语气的用法。根据下一句语境可知，他事先并没有得到警告，表示过去时间的虚拟语气，故选B。7. 答案C 本题考虚拟语气及责备的用法，句意：Mr.white（原本）8:30应该到会的，但他没露面。全句谈的是过去的事，故应使用should have done结构，表原本该做而没做的事。8. 答案D 本题考查情态动词用法，should（ought to）have done表示说话人对发生的事性责备故选D。9. 答案A 考语境及交际用语。前句建议：今晚咱们出去好好喝一顿吧。喝一顿应有个来由和原因，且多是为了庆祝某事，所以后句问：为何事（庆祝）？你是不是在竞赛中得了一等奖？这样才能表示后者惊讶、疑问和兴奋，what for：为何而做某事？其余均不合语境。10. 答案A 根据句意和句子的语气可知，第一空表示一种可能性，用may not speak 可能不会说；第二空表示有某种能力。关键是根据语境准确区别情态动词may与 can 表示可能性，某种能力的用法。11. 答案C 根据上下文语境及讲话人语气，选项动作表示经过努力才完成的。在这种语气的肯定句和疑问句中，常用be able to，在否定句中可用can。12. 答案D 根据讲话人语气可以知道，选项部分表示讲话是给对方的一种承诺，故应该选情态动词shall用于第二或第三人称用作主语的句子结构中。解题的关键是要正确理解shall用作情态动词在句中的用法。13. 答案 D 根据上下文和讲话人语气，选项情态动词表示过去本该做而实际未做的事， 故应选用should have done 或ought to have done。 must do， ought to do表示还未发生的动作。need have done常用于否定或疑问句，表示本来不必干某事。 14. 答案B 根据上下文语境及讲话人的语气可以知道，选项动作是对过去事情的推测，表示过去已经责怪，而宁愿该事情没有发生之意。故选Id rather not have done，其它三个选项表示对将要做的事情的态度。15. 答案A must 在此表示说话人的愿望或感到不耐烦，意思为偏要。句子意思为：正当我们要坐下来吃饭时，偏偏电话铃响了。其它选项无此意义，解题的关键是准确把握情态动词must的特殊意义在语境中的用法。16.答案 B cant表示一种客观可能性; mustnt表示绝对否定一定不；neednt不必；wont不愿意。根据语境及说话人语气，选项部分表示一种客观可能性。解题的关键是根据上下文语境，结合四个选项情态动词的意义进行分析判断，作出选择。17. 答案 C 根据上下文语境可以知道，选项动作为对现在事情的推测，故应选用must be doing，而选项A、B为对过去事情的推测，选项D表示将必须做的事情，均不符合句子情景。18. 答案C may not不可以，表示允许； mustnt一定不，表禁止； neednt没必要，表示一种建议；cant不能，表示某种可能性。根据说话人