课件类;人教版 英语 高二下学期Unit13 情态动词ppt.ppt

,ModalVerbs,possibility:can/could,may/mightcertainty:must,will,shouldability:can/could,beabletopermission:can/could,may/mightrequests:can/could,will/would,suggestions:could/may/might,shallnecessity:must,haveto,havegotto,needadvice:oughtto,hadbetter,语法特征,1.情态动词没有人称和数的变化,即情态动词第三人称单数不加-s(haveto,havegotto,beableto除外)。2.情态动词不能表示正在发生或已经发生的事情,只表示期待或估计某事的发生。,3.情态动词本身具有一定词义,但意思不够完整,不能单独做谓语,后接动词原形一起构成谓语部分(oughtto,haveto/havegotto,beableto除外)。4.情态动词无非谓语形式,即无不定式、分词等形式。,Sumup,1.can和beableto1)can(could)表示能力、可能,只用于现在式和过去式2)beableto可以用于各种时态。,只用beableto的情况：a.位于助动词后。b.情态动词后。c.表示过去某时刻动作时。d.用于句首表示条件。e.表示成功地做了某事时,只能用was/wereableto,不能用could。,注意:could还可不表示时态,只表示1)提出委婉的请求,回答中不可用could。-CouldIhavethetelevisionon?-Yes,youcan./No,youcant.2)在否定、疑问句中表示推测或怀疑。Hecouldntbeabadman.,2.may和might1)表示允许或请求;表示没有把握的推测;may放在句首,表示祝愿。e.g.MayGodblessyou!Hemightbeathome.注:might表示推测时,不表示时态。只是可能性比may小。,2)成语:may/mightaswell,后面接不带to的不定式，意为不妨。e.g.Ifthatisthecase,wemayaswelltry.,3.haveto和must1)两词都是“必须”的意思,haveto表示客观的需要,must表示说话人主观上的看法,即主观上的必要。e.g.Mybrotherwasveryill,soIhadtocallthedoctorinthemiddleofthenight.Hesaidthattheymustworkhard.,2)haveto有人称、数、时态的变化,而must只有一种形式。但must可用于间接引语中表示过去的必要或义务。e.g.Hehadtolookafterhissisteryesterday.,3)在否定结构中：donthaveto表示“不必”;mustnt表示”禁止”。e.g.Youdonthavetotellhimaboutit.你不必把这事告诉他。Youmustnttellhimaboutit.你不能把这事告诉他。,4.must表示推测1)must用在肯定句中表示较有把握的推测,意为“一定”。2)must表对现在的状态或现在正发生的事情的推测时,后面通常接系动词be的原形或行为动词的进行时。,e.g.Youhaveworkedhardallday.Youmustbetired.（对现在情况的推测判断)Hemustbeworkinginhisoffice.他一定在办公室工作呢。比较:Hemustbestayingthere.他现在肯定呆在那儿。Hemuststaythere.他必须呆在那儿。,表推测,不表推测,3)must表示对已发生的事情的推测时,要接完成时。e.g.Ididnthearthephone.Imusthavebeenasleep.4)must表示对过去某时正发生的事情的推测,后面要接不定式的完成进行时。,e.g.-Whydidntyouanswermyphonecall?-Well,Imusthavebeensleeping,soIdidnthearit.5)否定推测用cant.e.g.IfTomdidntleavehereuntilfiveoclock,hecantbehomeyet.,5.表示推测的用法can,could,may,might,must皆可表示推测,其用法如下：1)情态动词+动词原形,表示对现在或将来的情况的推测,此时动词通常为系动词。e.g.Idontknowwheresheis.ShemaybeinWuhan.,2)情态动词+动词进行时,表示对现在或将来正在进行的情况进行推测。e.g.Atthismoment,ourteachermustbecorrectingourexampapers.,3)情态动词+动词完成时,表示对过去情况的推测。e.g.Theroadiswet.Itmusthaverainedlastnight.,4)情态动词+动词的完成进行时,表示对过去正在发生事情的推测。e.g.Yourmothermusthavebeenlookingforyou.,5)推测的否定形式,疑问形式用cant,couldnt表示。e.g.Mikecanthavefoundhiscar,forhecametoworkbybusthismorning.注:could,might表示推测时不表示时态,其推测的肯定程度不如can,may。,6.情态动词+have+过去分词1)may(might)have+donesth.,can(could)have+donesth.表示过去,推测过去时间里可能发生的事情。,e.g.Philipmay(might)havebeenhurtseriouslyinthecaraccident.Philipcan(could)havebeenhurtseriouslyinthecaraccident.,2)musthave+donesth.,表示对过去时间里可能发生的事情的推测,语气较强,具有“肯定”的意思。e.g.-Lindahasgonetowork,butherbicycleisstillhere.-Shemusthavegonebybus.,3)oughttohavedonesth.shouldhavedonesth.本应该做某事,而事实上并没有做;否定句表示“不该做某事而做了”。,e.g.Yououghtto(should)havebeenmorecarefulinthisexperiment.Heoughtnottohavethrowntheoldclothesaway.(事实上已扔了。)注:oughtto在语气上比should要强。,4)neednthavedonesth.本没必要做某事e.g.Idressedverywarmlyforthetrip,butIneednthavedoneso.Theweatherwashot.5)wouldliketohavedonesth.本打算做某事e.g.Iwouldliketohavereadthearticle,butIwasverybusythen.,7.should和oughttoshould和oughtto都为“应该”的意思,可用于各种人称。e.g.-Oughthetogo?-Yes.Ithinkheoughtto.表示要求,命令时,语气由should(应该)、(hadbetter最好)、must(必须)渐强。,8.hadbetter表示“最好”hadbetter相当于一个助动词,它只有一种形式,它后面要跟动词原形。hadbetter(not)dosth.,e.g.Itisprettycold.Youdbetterputonmycoat.Shedbetternotplaywiththedog.hadbetterhavedonesth.表示与事实相反的结果,意为“(过去)本来最好”。e.g.Youhadbetterhavecomeearlier.,9.wouldrather表示“宁愿”wouldrather(not)dowouldratherthan宁愿而不愿wouldsoonerhadratherhadsooner表示宁愿、宁可的意思。e.g.IfIhaveachoice,Ihadsoonernotcontinuemystudiesatthisschool.,10.will和would1)wouldliketodo=wantto想要e.g.Wouldyouliketogowithme?2)Willyou?/Wouldyoulike?表示肯定含义的请求劝说时,疑问句中一般用some,而不是any。e.g.Wouldyoulikesomecake?,3)否定结构中用will,一般不用would,wontyou是一种委婉语气。e.g.Wontyousitdown?,11.need和dare这两词既可做实义动词用,又可做情态动词用。作为情态动词,两者都常用于疑问句,否定句和条件句。并注意回答用need提问的句子时，肯定回答用must。need作实义动词时后面的不定式必须带to,而dare作实义动词用时,后面的to时常可以被省略。,1)实义动词:need+n./todosth.2)情态动词:need,只用原形need后加do,否定形式为neednot.e.g.-Needyougoyet?-Yes,Imust./No,Ineednt.3)need,want,require,worth(形容词)后面接doing也可以表示被动。needdoing=needtobedone,Exercises,1.Aleft-luggageofficeisaplacewherebags_beleftforashorttime,especiallyatarailwaystation.A.shouldB.canC.mustD.will,B,2.How_yousaythatyoureallyunderstandthewholestoryifyouhavecoveredonlypartofthearticle?A.canB.mustC.needD.may,A,3.Theroomissodirty._wecleanit?Ofcourse.A.WillB.ShallC.WouldD.Do4.MyEnglish-Chinesedictionaryhasdisappeared.Who_havetakenit?A.shouldB.mustC.couldD.would,B,C,5.IsJohncomingbytrain?Heshould,buthe_not.Helikesdrivinghiscar.A.mustB.canC.needD.may,D,6.Iheardtheywentskiinginthemountainslastwinter.It_truebecausetherewaslittlesnowthere.A.maynotbeB.wontbeC.couldntbeD.mustntbe,C,7.Ithasbeenannouncedthatcandidates_remainintheirseatsuntilallthepaperhavebeencollected.A.canB.willC.mayD.shall8.IhearyouvegotasetofvaluableAustraliancoins._Ihavealook?Yes,certainly.A.DoB.MayC.ShallD.Should,D,B,9.Oh,Imnotfeelingwellinthestomach,I_somuchfriedchickenjustnow.A.shouldnteatB.mustnthaveeatenC.shouldnthaveeatenD.mustnteat,C,10.Iwasreallyanxiousaboutyou.You_homewithoutaword.A.mustntleaveB.shouldnthaveleftC.couldnthaveleftD.needntleave,B,11.Youcantimaginethatawell-behavedgentlemen_besorudetoalady.A.mightB.needC.shouldD.would12.Writetomewhenyougethome._.A.ImustB.IshouldC.IwillD.Ican,C,C,13.Mr.Bushisontimeforeverything.How_itbethathewaslatefortheopeningceremony?A.canB.shouldC.mayD.must,A,14.AreyoucomingtoJeffsparty?Imnotsure.I_gototheconcertinstead.A.mustB.wouldC.shouldD.might,D,15.MysistermethimattheGrandTheatreyesterdayafternoon,sohe_yourlecture.A.couldnthaveattendedB.neednthaveattendedC.mustnthaveattendedD.shouldnthaveattended,A,16.Sorry,Imlate.I_haveturnedoffthealarmclockandgonebacktosleepagain.A.mightB.shouldC.canD.will,A,17.Therewasalotoffunatyesterdaysparty.You_come,butwhydidntyou?A.musthaveB.shouldC.needhaveD.oughttohave,D,18.WhencanIcomeforthephotos?Ineedthemtomorrowafternoon.They_bereadyby12:00.A.canB.shouldC.mightD.need,B,19.IstayedatahotelwhileinNewYork.Oh,didyou?You_withBarbara.A.couldhavestayedB.couldstayC.wouldstayD.musthavestayed,A,20.Thefirespreadthroughthehotelveryquicklybuteveryone_getout.A.hadtoB.wouldC.wasabletoD.could,C,21.Jack