1、2013年高考第二轮复习英语广东版 语法热点突破第八讲情态动词和虚拟语气一、情态动词1情态动词具有以下三个特点：（1）后面接动词原形。（2）没有人称和数的变化。（3）变为疑问句或否定句时不需要加助动词，而是将情态动词移至主语前变为疑问句；在情态动词后加not，构成否定句。2“情态动词have done”表示推测、必要性情态动词have过去分词用法must have done表示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”can/could 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could have done可用于肯定句中，表示“可能已经
2、”；此外，还可表示过去没有实现的可能性，意为“本来可以”may/might （not）have done表示对过去已发生行为的推测，用于肯定句中，表示“也许已经”；在否定句中表示“可能不”，用might则表示语气更加不肯定should/ought （not）to have done用于肯定句中，表示“本该做某事，而实际上未做”；用于否定句中，则表示“不该做的事反而做了”neednt have done表示“本来没必要做某事”，指做了本来不必去做的事They must have_fallen （fall）asleep.I saw Mr. Wang just now.He couldnt have
3、_gone （go）to Beijing.You could have done better，but you were too careless.You should have come to the meeting earlier.3表示能力，can与be able to一般可互换，但be able to可用于将来时和完成时等时态；在表示过去具体某次能够成功做成某事时，只能用was/were able to。4表示请求许可，可说May/Might/Can/Could I .？但表示给予许可时，不能用might/could，即不说you might/could。5must与have to的区
4、别：must强调主观认为“必须”做某事，而have to 强调客观上要求“不得不”做某事；have to 有过去式（had to）和将来时（will have to）等时态；mustnt意为“不准”，dont have toneednt，意为“不必”。另外，must还可表示“硬要，偏要”。6should可表示“万一，竟然”。7表示“应该，应当”，should和ought to可互换，只是ought to的语气稍重；should强调主观看法，而ought to强调客观要求。8shall在陈述句中表示说话者给对方的承诺、决心、警告、威胁等；也可在法令、条约、规章中表示强制，意为“必须，应该”。还可
5、以用于Shall I/he .（要不要我/他？好吗？）。9might/may as well“不妨，还是为好”；had better do sth.“最好做某事”；would rather do sth.“宁愿做某事”。10“cannot help but动词原形”表示“不得不，只好”。I cannot help but go.11cannot/can never . enough/too .表示“再也不为过”。You cannot be careful enough to cross the road.二、虚拟语气类别用法例句if引导的条件从句与现在事实相反从句谓语动词：过去式（be用wer
6、e）主句谓语动词：should/would/could/might动词原形If he were here，he would help us.与过去事实相反从句谓语动词：had过去分词主句谓语动词：should/would/could/mighthave过去分词If I had been free，I would have visited you.与将来事实相反从句谓语动词：过去式/should动词原形/were不定式主句谓语动词：should/would/could/might动词原形If it should rain tomorrow，we would not go camping.其他状语
7、从句as if引导的状语从句中谓语动词用过去式（与现在事实不符）或过去完成式（与过去事实不符）The young man with long hair walks as if he were a girl.in order that/so that引导的状语从句中谓语动词用can/could/may/might/would等动词原形Turn on the light so that we can see it clearly.宾语从句demand，suggest，order，insist后接的从句中谓语动词用“should动词原形”He suggested that we （should）no
8、t change our mind.wish后的从句中谓语动词分别用过去式，过去完成式和should/would动词原形，表示与现在、过去和将来情况相反I wish I could be a pop singer.主语从句在It is necessary/important/strange that.，It is suggested/demanded/ordered/requested that.等从句中，谓语动词用“should动词原形”It is strange that such a person should be our friends.其他句型中It is （high）time t
9、hat.句型中that从句谓语动词用过去式或should动词原形Its high time that we left.would rather所接的从句中that从句谓语动词用过去式或过去完成式I would rather you stayed at home now.if only句型中动词常用过去式或过去完成式，表示强烈的愿望If only our dream had come true！即时训练在下列各句中填入适当的情态动词1（2011江西高考）It _ （not）be the postman at the door.Its only six oclock.2（2011辽宁高考）If y
10、ou _ go，at least wait until the storm is over.3（2011新课标全国高考）They _ have arrived at lunchtime but their flight was delayed.4（2011重庆高考）Why didnt you come to Simons party last night?I wanted to，but my mom simply _ not let me out so late at night.5（2011浙江高考）Hows your new babysitter?We _ （not）ask for a b
11、etter one.All our kids love her so much.6（2011陕西高考）I _（not）go through that bitter period without your generous help.7（2011陕西高考）Will you read me a story，Mummy?OK.You _ have one if you go to bed as soon as possible.8（2011上海高考）I _（not）worry about my weekendI always have my plans ready before it comes.9
12、There _（not）be any difficulty about passing the road test since you have practiced a lot in the driving school.10The World Wide Web is sometimes jokingly called the World Wide Wait because it _ be very slow.11I _ not stay for lunch.My brother is coming to see me.12If I _ plan to do anything I wanted
13、 to，Id like to go to Tibet and travel through as much of it as possible.13Tom，you _ not leave all your clothes on the floor like this!14（2011北京高考）I dont really like James.Why did you invite him?Dont worry.He _ not come.He said he wasnt certain what his plans were.15（2011湖南高考）No one _ be compared wit
14、h Yao Ming in playing basketball.Oh，you are really his big fan.用所给动词的适当形式填空1（2011北京高考）Where are the children？The dinners going to be completely ruined.I wish they _ （not be）always late.2（2011北京高考）Maybe if I _ （study）science，and not literature then，I would be able to give you more help.3（2011江西高考）We
15、_ （put）Johns name on the race list yesterday but for his recent injury.4If she _（come）here tomorrow，she _（tell）me that.We know she will fly to Beijing tomorrow.5If I _（see）him tomorrow，I will give it to him.6I wish I _（have）a room of my own when I was a boy.7I wish I _（go）to university next year，so
16、now I must study much harder.8I suggested that he _（go）there at once.9He insisted he _（send）to the city.10His expression suggested that he _（pass）the test.11I was ill yesterday.Otherwise，I _（take）part in the sports meeting.12If only I _（see）the film.13You _（come）to the conference yesterday.What was
17、the reason for your absence?14I _（work）out the problem，but I was too nervous.15They insisted that the boy _（go）with them.参考答案第八讲情态动词和虚拟语气1cant2must3should4would5couldnt6couldnt7shall8neednt9shouldnt10can11can12could13must14might15can1werent2had studied3would have put4came/were to come/should come；might tell5see6had had7will go8（should） go9（should） be sent10had passed11would have taken12had seen13should have come14could have worked15（should） go
