Grammar情态动词

ModalVerbI,Unit1,情态动词表示说话人的某种感情或语气，对某一动作或状态的某种态度。表示“需要、可以、必须、应当”等。,什么是情态动词？(ModalVerbs),情态动词的语法特征,1.一般不能单独做谓语,2.无人称和数的变化3.部分词有过去式（过去式可表过去，也可用于现在，表委婉）4.特殊：1）can/could:疑问句中，表“可能，猜测”may:肯定句中，“可能”；maynot:否定句中，“可能不”,2）cant/couldnt:“不可能”或“不能够”3）mustnt:“不准”4）shall/shallnt:2、3人称表命令、警告5）-MayI.?我可以.吗？-Yes,youmay./-No,youmustnt.6）-MustI.?我必须.吗？-Yes,please./youmust./Imafraidso.-No,youneednt./youdonthaveto.,情态动词的语法特征,1.表对过去事情的猜测或描述couldnthavedone:不可能（否定）mightnothavedone:可能已经不.（猜测）2.表与过去事实相反shouldhavedone本来该做却没做shouldnothavedone本来不该做却做了needhavedone本来需要做却没做neednthavedone本来不需要做却做了,情态动词过去式+havedone,IsntthatAnnshusbandthere?No,it_behim,Imsurehedoesntwearglasses.cantB.mustnotC.wontD.maynot,单选,2.Whereismypen?I_it.A.mightloseB.wouldhavelostC.shouldhavelostD.musthavelost,3.You_tothemeetingintheafternoonifyouhavesomethingimportanttodo.neednttocomeB.dontneedcomeC.dontneedcomingD.needntcome,4.-IsJohncomingbytrain?-Heshould,buthe_not.Helikesdrivinghiscar.A.mustB.canC.needD.may,5.Ithasbeenannouncedthatcandidates(候选人)_remainintheirseatsuntilallthepapershavebeencollected.A.canB.willC.mayD.shall,6.-Iheardtheywentskiinginthemountainslastwinter.-It_truebecausetherewaslittlesnowthere.A.maynotbeB.wontbeC.couldntbeD.mustntbe,7.MrBushisontimeforeverything.How_itbethathewaslatefortheopeningceremony?canshouldmaymust,8.-ShallItellJohnaboutit?-No,you_.Ivealreadytoldhim.needntB.wouldntC.mustntD.shouldnt,9.TotravelfromEnglandtoScotland,you_passport.mustnthavedontneedhaventgottoneednt,1.-Therewerealreadyfivepeopleinthecarbuttheymanagedtotakemeaswell.-It_acomfortablejourney.()A.cantbeB.mustnthavebeenC.shouldntbeD.couldnthavebeen,D,2.Thefirespreadthroughthehotelveryquicklybuteveryone_getout.()A.hadtoB.wouldC.couldD.wasableto,D,EXERCISES,4.Peter_comewithustonight,butheisntverysure.mustB.canC.mayD.will,C,5.-CouldIcallyoubyyourfirstname?-Yes,you_.A.willB.couldC.mayD.might,C,6.Sorry,Imlate.I_haveturnedoffthealarmclockandgonebacktosleepagain.mightB.shouldC.canD.will,A,7.-Excuseme,butIwanttouseyourcomputertotypeareport.-You_havemycomputerifyoudonttakecareofit.A.shantB.mightnotC.needntD.shouldnt,A,8.-WhencanIcomeforthephotos?Ineedthemtomorrowafternoon.-They_bereadyby12:00.A.canB.shouldC.mightD.need,B,9.Withsomuchworkonhand,you_toseethegamelastnight.A.mustntgoB.couldhavegoneC.shouldntgoD.shouldnthavegone,D,10.Johnny,you_playwiththeknife,you_hurtyourself.()A.wont;cantB.mustnt;mayC.shouldnt;mustD.cant;wouldnt,B,11.Thereisnolightinthedormitory.Theymusthavegonetothelecture,_?()A.didnttheyB.donttheyC.mustnttheyD.haventthey,D,12.Imissedthebus,soI_gohomeonfoot.A.mustB.mayC.canD.hadto,D,Thankyou.,1.can的主要用法是：A.表示能力：e.g.Thegirlcandanceverywell.B.表示许可e.g.Youcanstayhere.C.表示可能,猜测(否定,疑问句)e.g.Hecantbeathomeatthistime.D.表示请求e.g.Couldyoupleaselendmeapen?,can和could,2.could的主要用法是：A.could是can的过去式,表示与过去有关的能力和推测:e.g.Weallknewthattheyoungmancouldntbeadoctor.B.could可以代替can表示请求,但语气较can客气、委婉:,can&beableto,Can指一种固有的能力beableto某一次的具体行为，且是通过努力才能够做成事e.g.Hewasill,sohewasntabletofinishtheworkontime.,may常用来表示：A.表示请求、允许：比can较为正式:e.g.MayIcomein?Youmaygonow.B.表示说话人的猜测:“也许”“可能”:通常只用于肯定句和否定句中。,may和might,e.g.-IbelievethemanisfromEngland.-ButImaybewrong.Theguestmayarrivethisafternoon.在肯定句中，may的可能性比can高，may表示现实的可能性，can表示理论上的可能性。如：,Hemightgohometomorrow.说不定他明天会回家。表示现在的许可，语气比may较委婉，一般用于疑问句（包括间接疑问句），不可用于肯定句或者否定句。如:MightIhaveawordwithyou?我可以和你说句话吗？,will和would,1.will是助动词还是情态动词？will用于构成将来时是助动词。用于表示“意志”“决心”“请求”是情态动词。would亦同理。e.g.Iwilltellyousomethingimportant.我要告诉你一件重要的事情。,3.would比will客气委婉。e.g:Wouldyouhelpus,please?请您帮助我们，好吗？,（表请求）,shall和should,1.shall用于构成将来时是助动词。shall用于征求对方的意见，表示“决心”是情态动词。e.g:PerhapsIshallpayavisittoEnglandthiswinter.可能今年冬天我会去英国观光。（构成一般将来时,助动词）,Shallwegobytrain,Mom?妈妈，我们乘火车去好吗？（用于征求对方的意见，情态动词）Ishallgoatonce.我必须立即去。（表“决心”，情态动词）,2.should表示义务、建议、劝告，意为“应该”。“should+have+过去分词”表示本应该在过去做但没有做。e.g:Youshouldkeepyourpromise.你应该遵守诺言。Sheshouldhavepassedtheexam.她应该通过考试的。,must的主要用法,1.表示必然性。e.g:Manmusteat.人总要吃饭。2.表示强制或者义务。e.g:Youmustgetupearly.你必须早起来。,注意:mustnot的意思是不许可，不应该或者禁止。如：Wemustntwasteourtime.-MayItakethismagazineout?-No,youmustnt.must用于一般疑问句的时候，肯定回答应该用ye