unit2-healthy-eating--grammar情态动词.ppt

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1、Grammar情态动词情态动词情态动词表示推测表示推测不表示推测不表示推测cancouldmaymightshallshouldmustwillwouldoughttohavetoneed(neednt)dare(darent)usedto表示推测表示推测情态动词的重要用法情态动词的重要用法肯定的推测肯定的推测可能的推测可能的推测否定的推测否定的推测疑问的推测疑问的推测must 对将来对将来对现在对现在对过去对过去情态动词情态动词may,mightcant,couldntcan,could+V.+V.+havedone常见常见mustbe+bedoing+V.+V.+havedone+bedo

2、ing可以用可以用not表示表示“可能不可能不”+V.+V.+havedone+bedoing+V.+V.+havedone+bedoinge.g.Youngpeopleshouldlearnhowtousecomputers.Everycitizenoughttoobeylaw.Yououghtnottogo.should常表示劝告、建议、命令，与常表示劝告、建议、命令，与oughtto意义相近，但意义相近，但oughtto多表示责任、义务，语多表示责任、义务，语气强烈。在疑问句中通常用气强烈。在疑问句中通常用should代替代替oughtto。must&havetomusthaveto主观

3、客观主观客观时态现在，将来多种表推测询问意愿否定意禁止，不允许不必must&havetomust用用于于一一般般问问句句中中,肯肯定定回回答答用用must否否定定式式用用neednt或或donthaveto，做做“不不必必”,mustnt表示表示“禁止，不允许禁止，不允许”e.g.MustIfinishallassignmentsatatime?Yes,youmust.No,youneednt.Youmustntgetoffwhilethecarisstillmoving.must+havedone表示对过去已经发生的行为进行推测，意为“想必/准是/一定作了某事”。1.It must have

4、 rained last night,for the road was very muddy.昨晚 一定是下雨了，因为地上很泥泞。2.We must have learned 2,000 words by the end of last term.到上学期为止我们一定学了有两千个单词 。3.He must have gone to Beijing.他一定已经去北京了。can/could+havedone表示对过去的行为的怀疑和不肯定，通常用在否定句和疑问句中。1.Can they have won the basketball match?他们可能赢了篮球赛吗？2.It couldnt hav

5、e been Mr.Green.He has gone to New York.那不可能是格林先生的，他已经去北京了。could(不用can)+havedone,在肯定句中表示“本来能够而没能”，具有婉转的批评和责备之意。1.I could have passed my exam easily,but I made too many stupid mistakes.我本来能够轻易通过考试，但我犯了太多不该 犯的错误。2.You could have reported to me earlier.你本该早点告诉我的。may/might+havedone表示对过去已发生行为的推测，意为“也许/或许

6、已经”。一般只用于肯定句和否定句中，不用于疑问句。might比may更委婉、含蓄和不肯定。1.Its too late.I think he may have gone to bed.太晚了，我想他可能已经睡觉了。2.He may/might not have finished the work.他可能没有完成工作。might（不用may）+havedone表示“本来可能”，但实际上没有发生的事。另外，还可表示“本来应该或可以做某事”之意，含有轻微的责备语气。1.You might not have told her.你本可以不告诉他的。（事实上你告诉他了）2.You might have c

7、ome earlier.你本可以早点来的。（但没有这样）neednt+havedone表示做了本来不必去做的事。1.She neednt have gone to the station yesterday.昨天她本不必到火车站去的.（昨天她去了）2.You neednt have bought it.你本可不必买它的。（你买了）1.-I wonder why they are late?-They _ the train.A.cant have missed B.could missB.C.must have missed D.might missCA.2.Oh,Im not feeling

8、 well in the stomach.I _ so much fried chicken just now.B.A.shouldnt eat B.shouldnt have eaten C.C.mustnt eat D.mustnt have eatenB5.-Has Mike started?He said he would join in the party.-He _.He is a man of keeping his word.A.could have left B.must have leftC.cant come D.wont be comingA.6.-There were

9、 already five people in the car,but they managed to take me as well.B.-It _ a comfortable journey.C.A.cant be B.mustnt have been D.C.should be D.couldnt have been E.BD7.-Why hasnt Jane arrived yet?-She _ again in the morning?A.shouldnt have overslept B.may have turned off the alarm clockC.must have

10、no one t o call herD.should have someone to wake her up8.-Did you go to the movie the day before yesterday?-No.We _,but we decided not to.A.should have gone B.could go C.should go D.could have goneBA情态动词考题情态动词考题:1.-Didthetrainarriveintime?-No.It_twohoursago.A.musthavearrivedB.oughttohavearrivedC.mus

11、tarriveD.oughttoarrive2.MustIdrivetohishouseandpickupthechildren?No,.A.youshouldntB.youmightnot C.youneednt D.youmustntBC3.WedidntseeTomatthemeetingyesterday.Heit.A.mustnthaveattended B.cannothaveattended C.neednthaveattended D.wouldhavenotattendedB4.You_suchalongcomposition.Theteacheronlyaskedfor30

12、0words.Youhavewritten600.A.mustnthavewrittenB.couldnthavewrittenC.neednthavewrittenD.donothavetowriteC5.Thereissomeoneknockingatthedoor.itbeTom?A.canB.mustC.shouldD.oughtto6.Twoyearsago,myhusbandboughtmeabicycle.Ifyouliveintown,itisoftenfasterthanacarandyouworryaboutparking.A.mustnotB.maynotC.shouldnotD.donthavetoAD