情态动词1.助动词(auxiliary)主要有两类:基本助动词(primaryauxiliary)和情态助动词(modalauxiliary)。基本助动词有三个:do,have和be;情态助动词基本的有十四个:may,might;can,could;will,would;shall,should;must,need,dare,usedto,oughtto,hadbetter上述两类助动词的共同特征是,在协助主动词构成限定动词词组时,具有作用词的功能:2.情态动词无人称和数的变化,情态动词后面跟的动词需用原形,否定式构成是在情态动词后面加“not”。个别情态动词有现在式和过去式两种形式,过去式用来表达更加客气,委婉的语气,时态性不强,可用于过去,现在或将来。情态动词属非及物动词,故没有被动语态。情态动词1.can,could,beableto(可能,能够)2.may,might(可以,可能)3.must,haveto(必须,不得不)4.should,oughtto(应该,应当)5.need(需要)6.will,would(愿意)7.dare(敢)1.can1.表示能力Theparrotcanspeakthreelanguages.2.表示允许CanIborrowthebookfromthelibrary.3.有时会ShanghaicanbeverycoldinMarch.2.can与beabletocan表示能力,beableto表示经过努力而做成了某事,相当于managetodo/succeedindoing。有更多的时态3.can/could+have+p.p1.在否定、疑问句中表示“对过去的可能性猜测2.在肯定句中表示“本来可以做而未做”3.could提出委婉请求(回答不用could)1.Thedoorwaslocked.Shecouldn’thavebeenathome.2.Youcouldhavebeenmorecareful.3.Idon’tcareformoneybecausemoneycan’tbuylove.can’t不能,不可能4.cannot/cannever…too…cannot…enough无论怎么……也不过分;越……越好;非常……Ican’tthankyouenough.Sinceitisagoodthing,wecannotdoittoosoon5.cannothelpdoing…/cannothelpbutdo…cannotbutdo…“禁不住;不由得;不得不”6.cannothelp(to)do…不能帮助做1.May1.表示可能性2.表示允许、可以3.表示祝愿Might过去式;语气更委婉2.may/might+have+p.p表示对过去动作的推测“也许是……”Eg.1.Shemaybestillwaitingforus.2.MayIcomein?3.Mayyouhaveahappyholiday.Eg.Hemighthavespokentoheryesterday.委婉请求-----肯定答语?(might和could表示客气、委婉)1.--MayIsmokehere?--Yes,ofcourse/certainly/surelyyoumaypleaseI’dratheryoudidn’t./I’mafraidnotNo,youmustn’tyou’dbetternotpleasedon’tYoumaynotyoucan’t2.--CouldIuseyourbike?--Yes,youcan.3.--MightIaskyouaquestion?--Surely,youmay.4.--Wouldyoudomeafavour?--Ofcourse,Iwill5.--Wouldyouliketodoitforme?--Yes,I’dlike/loveto1.must1.表示必须、应该2.偏偏、偏要、硬要、非要(表示与说话人愿望相反或不耐烦)3.表示肯定的猜测,但只用于肯定句,4.而mustn’t表示“禁止、不准许、不可以”2.must、haveto1.must表示主观2.haveto表示客观需求3.must+have+p.pmustdo/be+adj./n对过去事情的肯定猜测。对现在事情的推测Eg.Theroadiswet.Itmusthaverainedlastnight.Whymustitalwaysrainonweekends?Ifyoumustsmoke,doitoutside,please.Youmustn’ttakephotoshere.It’sforbidden.havetodo(客观上实际情况)不得不做…1.Thereisnobushere,andyouhavetogoonfoot2.BecauseitisSunday,wedon’thavetogotoschool3.--Must/Needwehandinourcompositionnow?--Yes,youmust--No,youneedn’t/youdon’thaveto1.第一、三人称疑问句中表示“请求或征求对方意见Eg.ShallIgetyouacupofcoffee?2.第二、三人称陈述句中1、表示允诺“会(得到)。2、表示命令、警告、威胁、决心。3、在法律、条约、协定的文件中表示“义务、规定”shall1.Heshallbepunishedifhedisobeys.2.Ifyouworkwell,youshallhavehigherwages.3.Accordingtothelaw,halfofhismoneyshallbegiventothecityofVenice.Nothingshallstopusfromcarryingouttheplan.什么也不能阻止我们执行这项计划。(决心)Should:1.(表示“义务、责任、劝告、建议”)应该、应当2.(常规推测)应该会、想必会3.(表惊讶、遗憾)竟然、居然4.(与疑问词why,who,how等连用,表示意外、纳闷、惊讶等)究竟、到底5.(用于虚拟将来的条件句中)一旦、万一6.(用于表示命令、建议、请求的动词后面的that从句中,should可省略)应该、必须7.(用于以lest,forfearthat,incase引导的状语从句中)以免、唯恐8.(用于问句,表示询问、征求同意)可以、应该ShouldIturnonthelight?Will1、表示意愿、决心或愿望I’lltrymybesttoovercomethedifficulty.Ifyouwilllistentome,I’llgiveyousomeadvice2、表示请求(用于第二人称)Willyouhelpmetoputthesebooksinorder?3、用于叙述真理Oilwillfloatonwater4.(表示现在的习惯性、倾向性、必然性)惯于、老是、总是Boyswillbeboys/TomorrowwillbeSunday5.(表示功能)能、行What’sthematterwiththedoor?Itwon’tlockwould与usedtodo1.Would只能接表示动作的动词,表示过去习惯,现在可能仍如此Hewouldalwaysbethefirsttoofferhelp2.客观地、委婉地提出请求、愿望、看法等Wouldyouliketotellmehowtogetthere?3.虚拟语气的主句中Ifhewereintown,hewouldhelpmeusedtodo则还可以接表示状态的动词.现在不做了Peopleusedtothinkthattheearthwasflat.过去人们认为地球是平的。(现在人们不这么认为。)Heusedtobeaworker,usedn’the?didn’the?usen’the?Hedidn’tuse/usedn’ttocome.Usedhe/Didheusetocome?need与dareneed和dare既可用作情态动词,也可用作实义动词。need作情态动词,多用于否定句和疑问句。need没有过去式用作情态动词--NeedIcome?--我需要来吗?/DoIneedtocome?--Yes,youmust.--需要。Youneedn´ttelephonehimnow.你现在不必打电话给他。Idon´tthinkyouneedworry.我想你不必发愁。用作实义动词Youdon´tneedtodoityourself.你不必亲自做这件事。Weneedtotellthemthenews.我们需要把这消息告诉他们。Thetableneedspainting(tobepainted.).桌子需要油漆一下。dare作情态动词,多用于否定句、疑问句和条件句。dare有去式dared用作情态动词Shedarenotgooutaloneatnight.她晚上不敢一个人出去。HowdareyousayI´munfair?你竟敢说我不公平?Noneofthemdaredmentionthis.他们谁也不敢提这件事。Darehecrosstheriver?----No,hedaren’t用作实义动词Weshoulddaretogiveourownopinion.我们要敢于提出己的观点。Hedidnotdare(to)lookup.他不敢抬头看。Idaresayhe´llcomeagain.我想他会再来的。Iftheenemydarecome,theywillneverbeabletogetaway(Idaresay…为固定习语“译为我想…、大概…”)情态动词表责备may/mighthavedone(语气委婉)过去本可能做…而未做can/couldhavedone(语气委婉)过去本可能做…而未做shouldhavedoneoughttohavedone(语气强烈)过去本应该做…而未做needn’thavedone(无责备之意)过去本不必做…却做了didn’tneedtodo过去本不必做…也没做补充说明情态动词在一般疑问句中的回答:①Canyousing?②MayIcomein?③MustIhandinthebooknow?④NeedIfinishitnow?Yes,Ican.No,Ican’t.Yes,youmay.No,youmustn’t.Yes,youmust.No,needn’t/don’thaveto.Yes,youmust.No,youneedn’t.1.Youbuyagift,butyoucanifyouwantto.A.mustB.mustn'tC.havetoD.don'thaveto2.Ihavetoldyouthetruth.______Ikeeprepeatingit?A.MustB.CanC.MayD.Will3.I_______havewatchedthatmovie—it’llgivemehorribledreams.A.shouldn’tB.needn’tC.couldn’tD.mustn’t4.Markhavehurried.Afterdrivingattopspeed,hearrivedhalfanhourearly.A.needn’tB.wouldn’tC.mustn’tD.couldn’t5.—Itakethebookout?—I'mafraidnot.A.WillB.MayC.MustD.Need6.Justbepatient.You______expecttheworldtochangesosoon.A.can’tB.needn’tC.maynotD.whether7.—Ihaven’tgotthereferencebookyet,butI’llhaveatestonthesubjectnextmonth.—Don’tworry.You______haveitbyFriday.A.couldB.shallC.mustD.may