新高考版英语高中总复习专题二十一《情态动词和虚拟语气（讲解练）》教与学

1、专题二十一情态动词和虚拟语气高考英语课标导航情态动词和虚拟语气 考点清单高考常考点详解一、情态动词情态动词表示说话人的语气和态度,具有一定的词义,但不能单独作谓语, 它们要和行为动词或连系动词连用构成谓语。(一)情态动词的基本用法1.can,could用法例句can表示现在一般的能力,could表示过去一般的能力,即不表示做与未做某事Mary can speak three languages.玛丽能说3门语言。Tom could sing English songs at the age of 6.汤姆6岁就能唱英文歌了。用法例句表示请求、允许。在一般疑问句中could可代替can,但比ca

2、n语气更委婉,答语要用canCan/Could you help me?Yes, I can.你能帮我吗?可以。can表示具体事情发生的可能,常用于否定句、疑问句,表示疑惑、惊讶或不相信等意思。can表示理论上的可能时可用于肯定句。could表示推测时比can可能性小,可用于肯定句、否定句和疑问句That cant be true.那不可能是真的。(具体事情发生的可能,表示不相信)Accidents can happen in this weather. 这种天气可能会发生事故。(理论上的可能性)It could be weeks before we get a reply. 我们可能要等好几

3、个星期才得到回复。用于固定句型中:cant.too/enough(无论也不为过);cant help doing sth./cant help but do sth.忍不住做某事;cannot but do sth.不得不做某事I cant thank him too much.我怎么感谢他也不为过。I could not but admire her. 我不得不佩服她。续表2.may,might用法例句may表示请求或允许,意为:可以。might为may的过去式,常用于间接引语You may leave the book where it was.你可以把书放在原来的位置。She said

4、I might call her at the weekend. (间接引语) 她说我可以周末给她打电话。may,might 表示推测,用于肯定句,意为“可能”,may not意为“可能不”, 如表达“不可能”则用cantThis coat may be Peters.这件大衣可能是彼得的。 This coat may not be Peters.这件大衣可能不是彼得的。may表示祝愿May you succeed!祝你成功!用于固定句型中:may/might as well do不妨,还是做为好;may/might well+ do (=be very likely to do)很可能So

5、you might as well do what you love. 所以你不妨做你喜欢做的事情。Her appearance has changed so much that you might well not recognize her.她的模样变化如此大,你很有可能认不出她了。3.must用法例句表示必要性,意为:必须,其否定回答为neednt/dont have toMust I give up smoking? 我必须戒烟吗?Yes, you must.是的,你必须。/No, you neednt/dont have to.不,你不必。mustnt表示:禁止,为may作“可以”讲

6、时的否定式You mustnt smoke here.你不可以在这里吸烟。表坚持,意为:偏要,非要Must you make so much noise?你就非得弄出这么大声吗?表推断,用于肯定句,意为:一定,准是You must be tired after your long walk. 你走了那么长的路,一定累了。用法例句征求对方意见,与第一、三人称的一般疑问句连用Shall I/he go to see you? 我/他去看你,好吗?与第二、三人称的陈述句连用,表示说话者的意志,用来表达说话者给对方的命令、 指示、允诺。此种用法还可用来宣布法律、规定You shall have a n

7、ew dress for your birthday. 你过生日一定会有件新连衣裙。Each competitor shall wear a number. 每个参赛者要戴一个号码。(宣布规定)4.shall5.should用法例句=ought to,意为:应该。可表示义务上的“应该”,也可表示推测上的“按说应该”You should/ought to be listening.你应该听才对。(义务上的“应该”) He should/ought to arrive by now. 现在他按说应该到了。(推测上的“按说应该”) 竟然Its strange that he should be la

8、te.真奇怪,他竟然会迟到。用于条件从句中。意为:万一If I should be free tomorrow,Ill come. 万一明天有空,我就来。与表示命令、建议、请求、要求的动词或名词连用用于表示与将来事实相反的if从句中用法例句用于各种人称,表示主语的意愿和意志He will/would take you home.他愿意送你回家。与第二人称的一般疑问句连用,表示请求、建议Will/Would you go with me?你愿意和我一起去吗?will用来叙述目前的习惯;would表示过去的习惯He would get up early when he lived in the c

9、oun-try.他住在乡下时总是早起。6.will,would7.need,dare分类用法例句实义动词有人称和数的变化,可用于肯定句、否定句或疑问句中,构成否定句或疑问句时要用助动词do、does、didHe neednt do it.(情态动词)He doesnt need to do it.(实义动词)Dare you jump off the high wall?(情态动词)Do you dare(to) jump off the high wall?(实义动词)He dared not do it.(情态动词)He didnt dare(to)do it.(实义动词)Try it i

10、f you dare come here. (情态动词)情态动词没有人称和数的变化(dare可以有过去式dared),直接接动词原形,主要用于否定句和疑问句中,构成否定句和疑问句时不用助动词另外,dare作情态动词时,还可用于条件句中;作实义动词时,dare用于疑问句或否定句,后面的to也可省略;I dare say是习惯说法,意为“我想,大概”(二)“情态动词+have done”的用法情态动词+have done用法例句must have done想必/准是/一定做了否定式为:cant/couldnt+have doneIt must have rained last night,for

11、the road is quite muddy.昨晚一定下雨了,因为路很泥泞。can/could have done本来能够做过去可能会做Can he have gone to his aunts?他有可能去他姨妈家了吗?cannot/could nothave done过去不可能做过去没能够做He cannot have forgotten it.他不可能忘了那件事。情态动词+have done用法例句may/might have done也许/或许已经做了,一般只用于肯定句或否定句中(在否定句中表示“可能不”),不用于疑问句,用might则表示语气更加弱Its too late.I thi

12、nk he may have gone to bed.太晚了,我想他或许已经睡了。He may not have finished the work.他也许还没完成那项工作。should/ought tohave done本该做而实际上未做You ought to have done this ex-ercise more carefully.你本应该更仔细地做这个练习。续表情态动词+have done用法例句should not/ought notto have done本不该做而做了You shouldnt have told her the truth.你本不该告诉她真相。neednt

13、have done本不必做而做了You neednt have taken a taxi here,for it is very near to your house.你本来不必打车来这里的,因为这里离你家很近。had better have done当时最好做了(其否定式had bet-ter not have done表达相反的含义)You had better not have scolded her.要是那时你没责骂她就好了。续表情态动词+have done用法例句would rather have done宁愿当时做了(其否定式would rather not have done表达

14、相反含义,两者都表示“后悔”之意)I raised objections at the meeting,but now I would rather not have done that.我在会上提出了反对意见,但现在我宁愿没那么做。would like/love tohave done过去愿意做但未做成I would love to have gone to the party last night,but I had to work extra hours to finish a report.昨晚我本来很想去参加聚会的,但我得加班完成一个报告。续表二、虚拟语气1.虚拟语气用于非真实条件句

15、中 从句谓语形式主句谓语形式例句与现在事实相反过去式(be动词用were)would/should/could/might+动词原形If I were you, I would seize the chance.如果我是你,我就会抓住这个机会。与过去事实相反had+过去分词would/should/could/might+have+过去分词If you had taken my advice, you wouldnt have failed.如果你听了我的建议,你就不会失败。与将来事实相反过去式should+动词原形were to+动词原形would/should/could/might+动词

16、原形If he shouldnt come tomorrow, we would put off the meeting.如果他明天不来,我们就推迟这个会议。2.用于“(should+)动词原形”结构的虚拟语气(1)用于宾语从句中以下动词后的宾语从句常常使用虚拟语气,即谓语为“(should+)动词原形”。The teacher recommended that everyone (should)take an active part in the English party.老师建议每一个人都应积极参加英语晚会。易错提示suggest作“暗示”讲,insist作“坚持说”讲,由于后面宾语从句

17、谓语动词不再后于suggest和insist发生,故宾语从句的谓语动词不再使用虚拟语气形式(should+动词原形),而使用陈述语气。The smile on his face suggested that he was satisfied with our work.他脸上的微笑暗示着他对我们的工作很满意。The man insisted that he had never stolen the money.那个人坚持说他没有偷钱。(2)用于主语从句中It is desired/suggested/proposed/recommended/necessary/important/strang

18、e/natural/a pity/essential+that从句,从句的谓语动词用“should+动词原形”,should可以省略。It is suggested that the meeting(should)be put off till next week.人们建议将会议推迟到下周。It is strange that he (should)have treated his parents like that.(从句谓语动词的动作在主句谓语动词的动作之前发生时,要用“should have+过去分词”,should可以省略)真奇怪,他竟然那样对他父母。(3)用于表语从句和同位语从句中在

19、suggestion、proposal、order、idea、request、advice等名词后的表语从句和同位语从句中要用虚拟语气,其构成是“should+动词原形”,should可以省略。We all agreed to his suggestion that we (should)go to Dalian for sightseeing. 我们都同意他让我们去大连观光的建议。条件从句谓语形式例句从句谓语动词与主句谓语动词同时发生过去式(be动词用were)If only/How I wish I were a flying bird!我多希望我是一只会飞的鸟儿啊!He looks as

20、 if he were an artist.他看上去好像是名艺术家。从句谓语动词先于主句谓语动词发生had+过去分词If only I had seen the film!=How I wish I had seen the film!我要是看过那部电影该多好啊!She speaks English so fluently as if she had stayed in America for a long time.她说英语如此流利,好像她在美国待过很长时间似的。 从句谓语动词后于主句谓语动词发生would+动词原形He learns English so hard as if he wou

21、ld go to the U.S.A.他如此努力学习英语,好像他要去美国。课标必备点梳理一、虚拟语气在wish、as if、if only (=how I wish)后的从句中二、虚拟语气在“would rather+that从句”中条件从句谓语形式例句对现在或将来的虚拟过去式(be用were)Id rather they didnt hear of the news.我宁愿他们没有听到这个消息。对过去的虚拟had+过去分词Id rather I had not told him the bad news.我宁愿没有告诉过他那个坏消息。that从句谓语形式例句过去式或should+动词原形,且

22、should不能省略It is(high)time that you went/should go to school.你(们)该去上学了。三、虚拟语气在“It is (high) time+that从句” 中四、虚拟语气用于含蓄条件句中有时为了表达的需要,在虚拟语气中并不总是出现if引导的条件从句,而是通过其他手段来代替条件从句。Without your help,we couldnt have finished the work ahead of time.=But for your help,.=If it had not been for your help,.=Had it not

23、been for your help,.没有你的帮助,我们不可能提前完成这项工作。I was ill that day. Otherwise, I would have taken part in the sports meeting.(副词)我那天病了。否则,我就参加运动会了。He telephoned to inform me of your birthday,or I would have known nothing about it.(连词)他打电话通知了我你的生日,否则,我对此一点都不知道。I would write to her,but I dont know her addres

24、s.(连词)我要给她写信来着,可是不知道她的地址。A few hours earlier(=If you had come a few hours earlier),you would have been able to meet the famous writer.要是你早来几个小时,你就能见到那位著名的作家了。五、虚拟语气用于目的状语从句中在in case、for fear that、in order that、so that等引导的目的状语从句中,动词用“could/should/might/would+动词原形”,表示虚拟。 They left early for fear that

25、they would meet him. 他们动身很早,以免和他碰面。But I gave you a map so that you wouldnt get lost!但我怕你迷路,给过你一张地图!易混易错点突破几组易混情态(助)动词1.would,used to 用法例句would表示过去反复的动作,常与every day、often、frequently等连用When he was abroad, he would often read as many books as pos-sible.在国外时,他总是尽可能多地读书。used to表示过去的状态、习惯,但现在已经不存在She doesnt get up so early as she used to.她不像以前那样起得那么早了。 用法例句could表示过去的能力,但不表示是否做He could ride a bicycle at the age of 5.五岁时他就会骑自行车了。was able to表示过去有能力并且成功地做了,相当于managed to do sth.The fire spread very quickly but everyone