情态动词2.ppt

1、Unit 2 Sports events Modal verbs Warming-up exercises1.He _ speak English fluently.(表能力表能力)2.You _ work hard to win the gold medals.(表责任表责任/义务义务)3._we do some exercises this morning?(表征求对方意见表征求对方意见)4.-Might I watch TV after supper?-Yes,you _.A.may B.must C.might D.could5.-May I pick a flower in the

2、garden?-_.A.No,you need B.No,please C.No,you mustnt D.No,you wontmustcanShall A AC C一情态动词的语法特征一情态动词的语法特征 情态动词表示说话人对某一动作或情态动词表示说话人对某一动作或状态的态度，可以表示状态的态度，可以表示“可能可能”、“可以可以”、“需要需要”、“必须必须”或或“应当应当”等之意。等之意。情态动词情态动词没有人称和数的变化没有人称和数的变化。情态动词不能单独作谓语动词用，情态动词不能单独作谓语动词用，必须和不带必须和不带to的不定式连用构成谓语动的不定式连用构成谓语动词。词。Modal v

3、erbs:Modal verbs:general introduction二情态动词的语法功能二情态动词的语法功能 We can use modal verbs to talk about:abilitycertaintypermissionobligation make requests make suggestions make offers give advice 能力能力义务义务,责任责任确定确定允许允许 提出提出请求请求 提出提出建议建议提供提供帮忙帮忙提出提出忠告忠告Modal verbs:Modal verbs:general introduction情态动词情态动词1.can

4、could be able to2.shall 4.may might三常见情态动词的基本用法三常见情态动词的基本用法3.must have to 7.will would5.need dare6.ought to should8.情态动词情态动词+have done cancan表示能力表示能力,couldcould是其过去式是其过去式Some of us can use the computer now,but we couldnt last year.1.情态动词情态动词can,could和和be able to的用法的用法表示表示“客观的可能性客观的可能性”*吸烟往往会导致癌症吸烟往往

5、会导致癌症。Smoking can cause cancer.*It can be very cold here in winter.这的冬天有时会很冷。这的冬天有时会很冷。E.g:-Could I use your pen?(语气委婉语气委婉)-Yes,you can.No,you cant/mustnt.表示表示“请求请求”,主要用于疑问句中主要用于疑问句中,表示表示委婉委婉语气语气,过去式过去式could 比比can更加委婉更加委婉。肯定回肯定回答时答时,常用常用原形原形can,不可再用不可再用过去式过去式could。表示请求或许可表示请求或许可-Can I go now?-Yes,yo

6、u can.表示推测表示推测,常用于疑问句和否定句中常用于疑问句和否定句中This This cant/couldntcant/couldnt be done by him.be done by him.He couldnt have been to the city.区别区别 can can 与与be able tobe able to(1).be able to表示能力表示能力,有人称和数的变化有人称和数的变化,可用于各种时态可用于各种时态;(2).只表示能力时只表示能力时,can=be able to(3).was/were able to更侧重于更侧重于“过去做成过去做成了了某事某事”

7、=managed to do sth.=succeeded in doing sth.E.g:*He was able to swim across the river before the ship sank.【Practice】*He managed to get the radio repaired without any help.=He _/_ the radio repaired without any help.was able to getsucceeded in getting 2.shall用法用法 shall常用于常用于第一第一,三人三人称疑问句中称疑问句中,表示表示征求

8、对方意见征求对方意见,用于用于二、三人称二、三人称陈述句中表示陈述句中表示决心、命令、警告、允诺、决心、命令、警告、允诺、威胁威胁、强制等语气强制等语气。Shall he clean the blackboard for you?Take it easy.You _be offered a job in this company.Mike _spare no effort to study.(1)“The interest _be divided into five parts according to the agreement made by both sides.”declared th

9、e judge.A.may B.should C.must D.shallshallshallD表表“法律法规法律法规等文件中表等文件中表示义务或规定示义务或规定”(2)-Excuse me,but I want to use your computer to type a report.-You_ have my computer if you dont take care of it.A.shant B.might not C.neednt D.shouldnt(3)The boss said to the secretary,“If you work well,you _ have a

10、rise.”A.must B.ought C.shall D.would AC表表“警告警告”表表“允诺允诺”3.3.情态动词情态动词mustmust和和have tohave to的用法的用法:“must”与与“have to”都表示都表示“必须必须,不得不不得不”must:主观愿望主观愿望have to:客观需求客观需求,有时态有时态,人称和数的人称和数的变化变化.Ex:*The train leaves at 7 oclock.I _(must/have to)go now.*I dont like my watch.I _ (must/have to)buy a new one.hav

11、e tomustE.g:-你现在就得回家吗？你现在就得回家吗？-是的是的,我现在就得回家。我现在就得回家。不不,我现在不需要回家。我现在不需要回家。-Must you go home now?(必须必须)在疑问句中在疑问句中“must”表示表示“必须必须”的回答形的回答形式式 肯定肯定“Yes,sb.must.”;否定否定“No,sb.neednt.”或或“No,sb.dont(doesnt)have to.”*dont have to=neednt 没必要没必要-Yes,I must./No,I neednt.=I dont have to.否定句中用否定句中用cant/couldnt表示对

12、表示对现在现在的肯定推测的肯定推测 must do 表示对表示对过去过去的肯定推测的肯定推测 must have done肯定已经做了某事肯定已经做了某事must表示肯定的推测表示肯定的推测,只能用于肯定句只能用于肯定句指指“一定一定,肯定肯定”;Practice*你现在一定困了你现在一定困了/不困。不困。He must have watched the football match last night.You must be/cant be sleepy now.*你现在一定困了你现在一定困了,不是吗不是吗?*他昨晚一定看足球比赛了。他昨晚一定看足球比赛了。You must be slee

13、py now,arent you?*He must have watched film last night,_?*He must have watched film,_?A.hasnt he B.mustnt he C.didnt he D.hadnt heCAmustnt 表示表示“不准、禁止不准、禁止”*你们不准在学校吸烟。你们不准在学校吸烟。You mustnt smoke at school.must有时表示有时表示“偏要偏要”,含含“责备责备,抱怨抱怨”之意之意(1)我已经跟你讲过很多遍了我已经跟你讲过很多遍了,为什么你为什么你偏要偏要 在课堂上讲话呢？在课堂上讲话呢？(2)现在已

14、是午夜了现在已是午夜了,你你偏要偏要这个时候弹这个时候弹 钢琴钢琴吗吗？I have told you many times._?It is midnight._?Must you play the piano nowWhy must you talk in class 4.4.may/might may/might (1)表示表示“许可或请求许可许可或请求许可”时时:might,比较委婉比较委婉,一般多用于一般多用于疑问句疑问句;might表示征询对方意见或表示请求时表示征询对方意见或表示请求时,回回 答应相应使用答应相应使用 may;表示允许表示允许(肯定句肯定句)和请求和请求(疑问句疑问

15、句);若回答若回答 表示表示“不可以不可以/不准不准”时时,一般用一般用mustnt.E.g:-May/Might I use your dictionary?-Yes,_./No,you _.may/canmustnt(2)表猜测时表猜测时,“may,might”能用于陈述句中能用于陈述句中,有有“或许或许,大概大概”之意之意.may的可能性较大的可能性较大,might的可能性最小的可能性最小;(3)may可以表示可以表示“祝愿祝愿”,might不能这样用不能这样用E.g:*希望上帝保佑你希望上帝保佑你!May God bless you!*Rose may be busy now.*Ros

16、e might have returned home,but Im not sure.*但愿你快乐但愿你快乐!May you be happy!Practice:1、-Might I watch TV after supper?-Yes,you _.A.may B.must C.might D.could2、-Where is my dictionary?I remember I put it here yesterday.-You _it in the wrong place.A.must put B.should have put C.might put D.might have put

17、AD 5.should&ought toShould&ought to含义相近，都可表含义相近，都可表“责任，责任，义务义务”常可互换。常可互换。区别在于区别在于:ought to常指按义务，法律，规定等常指按义务，法律，规定等“应当应当”。Should则指主观上按道理应该。则指主观上按道理应该。ought to 比比should语气更强烈语气更强烈 shouldshould表义务，按道理表义务，按道理“应该应该”,含劝告含劝告,建议语气建议语气You should be polite to your teachers.表主观上推测表主观上推测,“照理应该照理应该”The film shoul

18、d be very good as it is starring first-class actors.表意外或惊讶语气表意外或惊讶语气,译译竟然竟然You should wear slippers(拖鞋拖鞋)at work!ought to ought to表义务表义务,应该应该(因责任义务因责任义务,法律规定等做法律规定等做)He is your father.You ought to take care of him.表推测表推测,应该应该 He ought to know my telephone number.6.will,would表意愿或意志表意愿或意志,决心决心,would为过

19、去时为过去时I will not do that again.表征求意见或提出请求表征求意见或提出请求,常用于疑问句常用于疑问句中中,would语气更委婉语气更委婉.Will/Would you pass me the book?表经常性表经常性,习惯性动作习惯性动作,“总会总会”=used to The old man would have a smoke under a big tree every afternoon.表功能表功能,“能能,行行”The machine wont work.7.need/dare 7.need/dare可兼做行为动词的情态动词：可兼做行为动词的情态动词：n

20、eed need、daredare -Need I tell him everything?-Yes,you must.-No,you neednt/dont have to.情态动词(+动词原形动词原形)行为动词 .needdare敢敢 1.1.无人称和数的变化无人称和数的变化;2.2.尤其用于：尤其用于：*否定句及疑问句中否定句及疑问句中;3.3.常以常以neednt 和和darent 的形式出现的形式出现;4.4.dare有其过去时有其过去时dared.多用于肯定句多用于肯定句;need to do dare to do 1.判断正误判断正误:How dare you say such

21、a thing?How dare you to say such a thing?He darent to speak English before such a crowd,did he?He darent speak English before such a crowd,dare he?neednt have done 过去没有必要做某事而实际上却做了过去没有必要做某事而实际上却做了(虚拟）虚拟）can/could(not)have done 过去本可以过去本可以(不不)做某事却没做做某事却没做(做了做了)（虚拟）（虚拟）过去可能已经做了某事（对过去的推测）过去可能已经做了某事（对过去的

22、推测）may/might have done 过去可能已经做了某事过去可能已经做了某事 （对过去的推测）（对过去的推测）8.情态动词情态动词+have done表示对已经发生事情推测、表示对已经发生事情推测、责怪、后悔、遗憾等。责怪、后悔、遗憾等。must have donemust have done should/ought to have doneshould/ought to have done肯定已经做了某事（对过去的推测）肯定已经做了某事（对过去的推测）本应该做某事却没做本应该做某事却没做(虚拟）虚拟）应该已经做了某事（对过去的推测）应该已经做了某事（对过去的推测）would ha

23、ve done本来会做某事，却没做本来会做某事，却没做 (虚拟）虚拟）v表示推测表示推测(可能性可能性)时时,按语气强弱按语气强弱 强强弱弱mustmay cant,couldntcan,couldmightshould ought to1.The weather turned out to be fine yesterday.I_ the trouble to carry my umbrella with me.A.should have taken B.could have taken C.neednt have taken D.mustnt have taken2.-Ill tell M

24、ary about her new job tomorrow.-You _her last week.A.ought to tell B.would have told C.must tell D.should have told C CD DPractice3.She _ have left school,for her bike is still here.A.cant B.wouldnt C.shouldnt D.neednt4.-I cant find my purse anywhere.-You _ have lost it while shopping.A.may B.can C.

25、should D.would5.-I stayed at a hotel while in New York.-Oh,did you?You _with Barbara.A.could have stayed B.could stay C.would stay D.must have stayed AAA1.What sort of house do you want to have?Something big?-Well,it _ be bigthats not important.A.mustnt B.neednt C.cant D.wont2.改错改错 Mr.Li mustnt have

26、 gone to Shanghai because I saw him a few minutes ago.BBack cantmust表推测只用于肯定句表推测只用于肯定句,否定句中表推测否定句中表推测用用cant;mustnt 指指“禁止、不准禁止、不准”1.He said that the bike _ stolen and that he_ have to telephone the police.A.was,would B.has,will C.has been,will D.had been,would not2.Mr.Bush is on time for everything.H

27、ow _ it be that he was late for the opening ceremony?A.can B.should C.may D.must DBackA1.1.It has been announced that candidates _ remain in their seats until all the papers have been collected.A.can B.will C.may D.shall 2.You cant imagine that a well behaved gentleman _ be so rude to a lady.A.might

28、 B.need C.should D.would DCBack1.Tom,finish your homework first,or you _ watch TV!A.shant B.couldnt C.neednt D.may not2.-She looks very happy.She _ (must/might)have passed the exam.-I guess so.Its not difficult after all.ABackmust1.-Could I borrow your dictionary?-Yes,of course you _.A.might B.will

29、C.can D.should2.Hearing the steps of the police,the thief _ move at all.A.dares not B.dared not to C.didnt dare to D.not dareCCBack1.-Where is my dictionary?I remember I put it here yesterday.-You _it in the wrong place.A.must put B.should have put C.might put D.might have put 2.-Is John coming by t

30、rain?-He should,but he _not.He likes driving his car.A.must B.can C.need D.mayDDBack表对过去可能性的推测。表对过去可能性的推测。1.Mike,look at the time._you play the piano at such a late hour?A.Must B.Can C.May D.Need 2.She is already two hours late.What _to her?A.may have happened B.can have happened C.should have happe

31、ned D.must happenABackB1.If it were not for the fact that she _sing,I would invite her to the party.A.couldnt B.shouldnt C.cant D.might notC2.It is recommended that passengers _ keep their cell phones on when the plane is landing.A.not B.need not C.could not D.would not Backcant 表能力表能力,此处表示她本身能唱歌的此处

32、表示她本身能唱歌的一个客观事实一个客观事实。A1.I didnt hear the phone.I _asleep.A.must be B.must have been C.should be D.should have been2.My suggestion is that Tom_ abroad and he stay here until the project completes.A.send B.should not send C.be sent D.not be sentBBackD1.A _ candle _ the faces of everybody in the room.

33、They all looked tired.A.lit,lit up B.lit up,lit C.lighted,lit up D.lighted,lit2.There is a party tonight _ our new president,and I am _ to be invited.A.in honor;honored B.in place of;of great honorC.in great honor;in favor of D.in honor of;honoredBackDCHomework1.Review the modal verbs we learnt today;2.Finish Step III Practice of Learning plan 4-5.