高考英语语法突破专题3情态动词和虚拟语气讲义.docx

1、高考英语语法突破专题3情态动词和虚拟语气讲义专题3情态动词和虚拟语气框架结构图情态动词的核心考点1.can/could和be able to的用法(1)can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。Her mother can speak French.The wounded man was still able to get

2、to the village and was saved by the villagers in the end.(2)can/could表示猜测“可能”，一般用于疑问句和否定句。Can the news be true?It cant be true.Someone is knocking at the door.Who could it be?(3)can可以表示理论上的可能性，指常有的行为或情形，意为“有时会”。Anybody can make mistakes.(4)表示请求、允许(表请求时，口语中常用could代替can使语气更委婉，回答时用can)。Can I go now?Cou

3、ld I come to see you tomorrow?Yes，you can.(否定答语可用No，Im afraid not.)(5)表示惊异、怀疑、不相信的态度(主要用于否定句、疑问句或感叹句中)。How can that be true？I cant believe my eyes and ears.How could you be so careless?(6)can的特殊用法。can but只好；cant but不得不；cant.too再也不为过，越越好I can but wait.I cant but wait.You cant be too patient to the cu

4、stomers.2.may和might的用法(1)表示允许、请求，might比may的语气更委婉一些。May I watch TV now?Yes，you may.(Yes，please.)No，you mustnt.(No，youd better not.)(2)表示可能性时，might比may的可能性小，may表示的可能性比can小(主要用于陈述句、肯定或否定句，疑问句用can代替)。The story may not be true.(3)表示祝愿(不用might)May you succeed!(4)may/might as well最好还是，不妨You might as well d

5、o it now.(5)may/might well很可能He may well be late for class.3.must，have to和ought to的用法(1)must表示“必须，应该，一定要”。强调主观看法，只有现在时形式，否定式是must not(mustnt)。must开头的问句，其否定回答要用neednt或dont have to来表达。We must do it now.Must I hand in the paper today?Yes，you need/must.No，you neednt/dont have to.表示必然的结果。All men must die

6、.还可表示主语固执、偏要做他人不希望做的事。It cant help；he must do that.(2)have to着重客观需要，能用于更多时态(过去时或将来时)。He will have to be there before ten.(3)ought to表示义务和责任，意为“应该”，比should语气要强。You ought to take care of yourself.4.need和dare的用法(1)need表示“需要，必要”，只能用于否定句和疑问句。在肯定句中，常用must和have to代替。You dont need to do it at once.Need I co

7、me?(2)dare表示“敢”，通常用于否定句、疑问句和条件状语从句中。I darent ask her for a rise.Dare you go home alone at eleven in the evening?If you dare speak to me like that again，youll be sorry.(3)need和dare的特殊用法need表“需要”时，可用want，require代替。The desk needs repairing/to be repaired.The desk wants/requires repairing/to be repaired

8、.dare作实义动词时，在肯定句中要接to，在疑问句和否定句中to可省去。He dares to catch a snake.I do not dare (to) complain.Do you dare (to) swim in the river?5.will和would的用法(1)will表示请求、建议，常用于第二人称。Will you please go with me?表示意愿、决定、允许。I will never do that again.表示习惯性动作或某种倾向，意为“总是，惯于”，通常用于第三人称。Rosa will always be late for school.(2)

9、would表示请求、建议，比will委婉，指现在时间，多用于第二人称。Would you like a cup of tea?表示过去习惯性动作或某种倾向。We would play badminton on Sundays.6.shall和should的用法(1)shall用于第一、三人称，在问句中表示征求对方意见或请求。Shall I come in?When shall he be able to leave the hospital?用于第二、三人称的陈述句中，表示命令、允诺或威胁。You shall do as your father says.He shall have the b

10、ook when I finish reading.He shall be punished.(2)should表示责任、义务，意为“应该”。You should listen to your doctors advice.表示惊讶语气，意为“竟然”。You should wear slippers in class.用于条件句，表示“假如，万一”；省去if，should可提至句首。Should you be late，apologize to the teacher.7.情态动词表示推测或判断的用法情态动词对现在和未来的推测对过去的推测使用场合mustmustdomust have done

11、肯定句may/mightmay/mightdomay/might have done肯定句、否定句can/couldcan/could docan/could have done否定句、疑问句(could可用于肯定句)shouldshould doshould have done肯定句、否定句、疑问句情态动词have done的用法：(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”。You should have told me about it earlier.You shouldnt hav

12、e said such words to your parents.(2)ought to have done表示“本应该做某事而实际上未做”，而ought not to have done则意为“本不应该做某事而实际上做了”。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“本无必要做某事而实际上做了”。You neednt have walked so quickly since time was eno

13、ugh.(4)could have done表示“本来有可能做某事而事实上未做到”。I could have come on time，but my car broke down on the way.(5)may/might have done表示“过去可能发生过某事”或“本来应该/可以做某事(实际上没做)”。You might have given him more help，but you were so busy.虚拟语气的核心考点1.虚拟语气用于条件状语从句(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用一般过去时(be动词用were)，而主句中的谓语动词用“would/s

14、hould/could/might动词原形”。If I were you，I would buy that house.If he had time，he should go with you.(2)表示与过去事实相反的假设，条件状语从句中的谓语动词用过去完成时，主句中的谓语动词则用“would/should/might/couldhave过去分词”。If he had taken my advice，he would have succeeded in passing the examination.(3)表示与将来事实相反的假设，条件状语从句中的谓语动词用一般过去时或“should/wer

15、e to动词原形”，而主句中的谓语动词则用“would/should/could/might动词原形”。If it rained/should rain/were to rain tomorrow，the football match would be put off.(4)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。If they had worked hard，they would be very tired now.(从句说的是过去，主句指的是现在)2.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”

16、表示不能实现的愿望，译为“要是就好了”。表示现在没有实现的愿望，从句中的谓语动词用一般过去时(be动词用were)；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”；表示过去未能实现的愿望，从句中的谓语动词用“had过去分词”。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”等动词后的宾语从句中，谓语动词用“should动词原形”，should可以省略。常见的这类动词有：suggest，

17、advise，propose，demand，require，insist，request，command，order等。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。表示“建议、要求、命令”等的名词，如advice，idea，order，demand，plan，proposal，suggestion，request等，其后的表语从句和同位语从句中谓语动词用“should动词原形”，should可以省略。His s

18、uggestion 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、不相信或理应如此等。It is necessary that we (should) clean the room every day.It was a pity/a shame that you (should) be so careless.It will be desired

19、that she (should) finish her homework this afternoon.注意：这种从句表示的是事实。如果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从句也可用陈述语气。It is a pity that you cant swim.3.虚拟语气在其他场合的运用(1)虚拟语气在as if/though，even if/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(be动词用were)；指将来状况，则用would/could/might动词原形。He spok

20、e as if he had known it.You look as if you didnt care.Even if she were here，she could not solve the problem.(2)虚拟语气用于句型“It is (high) time (that).”中，从句的谓语动词用一般过去时(be用were)或“should动词原形”，should不可省略，意为“(现在)该”。Its time that I picked up/should pick up my daughter.(3)虚拟语气用在if only引导的感叹句中，对现在的虚拟用一般过去时(be用we

21、re)；对过去的虚拟用过去完成时。If only I were a pilot.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。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。Would you like something to drink?I would rather not tell yo

22、u.(5)would rather虚拟语气的用法。would rather sb.did sth.是对现在的虚拟；would rather sb.had done sth.是对过去的虚拟。1.表达的单调性例如在写一封回信向好友表达建议时，重复使用You should.既显得单调，同时强硬的语气影响了交际效果。我们可以灵活多样地表达建议，如Youd better./You might as well./Why not.？等。2.情态动词搭配错误.单句语法填空I cant find my purse.I could/mighthaveleft(leave) it in the supermarke

23、t yesterday，but Im not sure.(2018天津)解析句意为：我找不到我的钱包了，昨天我有可能把它落到超市里了，但我不确定。根据句中时间状语yesterday可知，是对过去发生事情的推测，故用“情态动词have done”，再根据后句but Im not sure可知，此推测为不能肯定的推测，故用could/might have done。.单句改错(每小题仅有1处错误)1.As a kid，I loved to watch cartoons，but no matter how many times I asked to watch them，my parents wou

24、ld not to let me.(2018全国)解析would (not)表示“意愿”时后面直接跟动词原形，故把to删除。2.Then he and my mother would have had a drink while she prepared dinner and they would talk about his day and hers.(2016浙江)解析根据语境可知，此处是描述的过去的一种习惯，故用would do表示“过去常常做”。would have done表示对过去事情的假设，意为“本来会做”。3.Some classmates suggest we can 或 g

25、o to places of interest nearby.(2016全国)解析suggest表示“建议”时，后面的宾语从句的谓语动词要用should do形式，should可以省略，故答案有两种改法。4.We must ways to protect our environment.(2015全国)解析情态动词后面要接动词原形。题组一情态动词集训.单句语法填空1. I dont know where she is；she may be in Wuhan.2.The road is wet.It must have rained last night.3.You shall be punis

26、hed if you cheat in the exam.4.Dont worry.Ive just sent an ambulance to you.They should be there any second.5.I should have gone to the school library，but it rained heavily，so I did not.单句改错(每小题仅有1处错误)1.You had better not to have stayed there，but you did.2.My punishment lasted a year.Meanwhile，I fou

27、nd out that with more patience I make my toys last.My attitude changed from then on.3.I have been practising for three weeks now，but I still get used to itin fact，Ive nearly killed three people.4.Thank you for all you have done for me.Mom，though I may often say it，I do love you.5.Judging from what y

28、ou said，he ought succeed.题组二虚拟语气集训.单句语法填空1.He walked in as if he hadbought(buy) the school.And the word quickly got around that he was from New York City.2.If you hadtold(tell) me the news yesterday，I wouldnt be so worried now.3.Sorry，I am too busy now.If I had(have) time，I would certainly go for an

29、 outing with you.4.He was very busy yesterday；otherwise he wouldhavecome(come) to the party.5.Its time that our government took/shouldtake(take) measures to improve the quality of the buildings.6.Mr Li insisted that the sports meeting (should)beput(put) off because of the bad weather.单句改错(每小题仅有1处错误)

30、1.If I 10 years younger，I would start all over again.2.If we had enough rain last year，we could have gained a good harvest.3. I to be a teacher in the future，first of all，I would try my best to give students lessons.4.George is going to talk about the geography of his country，but Id rather he more o

31、n its culture.5.The chairman demanded that people present every effort to protect the polar bear against dying out.语法填空(情态动词和虚拟语气专练)Lucy is an outgoing lady.She 1.can play many kinds of musical instruments.Actually，she 2.could play the piano when she was 8 years old.Lucy also keeps taking exercise every day.She says that she ha