情态动词用法详解

情态动词的定义情态动词是一种本身有一定的词义，表示说话人的情绪、态度或语气的动词，但不能单独作谓语，只能和其他动词原形构成谓语。Wecanbethereontimetomorrow.MayIhaveyourname?Shallwebeginnow?Youmustobeytheschoolrules.情态动词数量不多，但用途广泛，主要有下列：can(could),may(might),must,need,oughtto,dare(dared),shall(should),will(would).情态动词的位置情态动词在句中放在谓语动词之前，谓语动词前若有助动词，则在助动词之前，疑问句中，情态动词放在主语之前。Icanseeyou.Comehere.Hemusthavebeenaway.WhatcanIdoforyou?你要什么？Howdareyoutreatuslikethat!情态动词的特点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，过去式可以用来表达更加客气、委婉的语气，时态性不强，可用于过去，现在或将来。Hecouldbeheresoon.他很快就来。Wecan'tcarrytheheavybox.I'msorryIcan'thelpyou.情态动词的用法1.can(could)表示说话人“能,可以,同意,准许”,以及客观条件许可,could为can的过去式。Canyoupassmethebooks?Couldyouhelpme,please?Whatcanyoudo?你能干点什么呢?Canyoubesure?你有把握吗?can和could只能用于现在式和过去式两种时态，将来时态用beableto来表示。beableto还表示过去具有某种能力并实施了。Hecouldhelpusatall.他完全可以帮助我们。Withtheteacher’shelp,IshallbeabletospeakEnglishcorrectly.有老师的帮助,我将能准确地讲英语。2.may(might)“可以”，表示说话人同意，许可或请求对方许可。Youmaytakethebookhome.MayIcomein?我可以进来吗?MayIuseyourdictionary?Youmayputonmoreclothes.Hesaidhemightlendussomemoney.他说他可以借给我们一些钱。may否定式为maynot,缩写形式是mayn’t。might是may的过去式，有两种用法，一种表示过去式，一种表示虚拟语气，使语气更加委婉、客气或对可能性的怀疑。Hetoldmehemightbehereontime.MightIborrowsomemoneynow?Hemightbealive.他可能还活着。3.must“必须；应该；一定；准是”，表示说话人认为有必要做某事，命令、要求别人做某事以及对事物的推测。must用来指一般现在时和一般将来时，过去式可用haveto的过去式代替。Imustfinishmyworktoday.Youmustn'tworkallthetime.MustIreturnthebooktomorrow?Aftersuchalongwalk,youmustbetired.走了这么长的路,你一定累了HemustbethemanIamlookingfor.他一定是我要找的人。Hehadtogobecauseofsomebody’scallinghimthatday.那天他要走，因为有人叫他。值得注意的是：（1）must+have+过去分词，表示现在对过去事物的推测。Hemusthavetoldmyparentsaboutit.Hemusthavereceivedmyletternow.It'ssixo'clockalready,wemusthavebeenlateagain.（2）must和haveto的区别:must表示说话人的主观思想,haveto“不得不,必须”,表示客观需要,客观条件只能如此。Youmustdoitnow.你必需现在就干。(说话人认为必须现在干)Ihavetogonow.我得走了。(客观条件必须现在走)Youmustbehereontimenexttime.Ihavetocookformychild.4.need情态动词，“需要”，多用在否定式或疑问句中.NeedIattendthemeetingtomorrow?Youneednothandinthepaperthisweek.这一周你不必交论文。need作情态动词的用法完全和其他情态动词一样，但need还可当作实义动词使用，这时need就象其他动词一样，有第三人称，单复数，后面加带to的动词等特性。Ineedabiketogotoschool.Doyouneedadictionary?Sheneedsanecklace.注意：“needn‘t+have+过去分词”表示过去做了没必要做的事情。Youneedn'thavetakenitseriously.这件事情你不必太认真。5.dare作情态动词,“敢”，多用在否定或疑问句中。Dareyoucatchthelittlecat?Thelittlegirldarenotspeakinpublic.dare除用作情态动词外，更多的是当实义动词使用，用法同实义动词一样，要考虑人称，单复数，时态等。Doyoudaretowalkinthedark?Hedoesn'tdaretotelltheteacherwhathappenedthatday.6.ought“应当；应该”，后面跟带有to的动词不定式。Yououghttoreadthesebooksifyouwanttoknowhowtorepairthemotorcar.如果你想知道如何修理汽车,你应该读这些书。Yououghttobringthechildhere.你应该把孩子带来。ought+tohavedone句型,指过去动作,表示一件事情该做而未做。Yououghttohavebeenhereyesterday.oughtnottohavedone句型,表示一件不该做的事情却做了。Yououghtnottohavetakenthebookoutofthereading-room.7.will(would)表决心、愿望。would为will的过去式,可用于各人称。I'lldomybesttocatchupwiththem.I'llneverdoitagain,that'sthelasttime.我再不会做那件事情了,这是最后一次。Hesaidhewouldhelpme.他说他会帮助我。will,would用于第二人称疑问句表示说话人向对方提出请求或询问,用would比will更婉转,客气。8.shall,should表示命令,警告,允诺,征求,劝告,建议,惊奇。Youshouldhandintheexercisebook.Thisshouldbenoproblem.这应该没问题。Shallwegonow?WhyshouldImeethim？为什么我要见他?It'shot.Willyouopenthewindows?Willyouhelpmetoworkitout?Wouldyoulikesomecoffee？情态动词专练题1.Putonmoreclothes.Youbefeelingcoldwithonlyashirton.A.canB.couldC.mustD.would2.—MustIdrivetohishouseandpickupthechildren?—No,________.A.youshouldn'tB.youmightnotC.youneedn'tD.youmustn't3.Youtoattendthemeeting,butyoudidn't.A.shouldcomeB.wouldhavecomeC.cameD.shouldhavecome4.Wedidn'tseeTomatthemeetingyesterday.Heit.A.mustn'thaveattendedB.cannothaveattendedC.needn'thaveattendedD.wouldhavenotattended5.Tomwentonfoot,buthebybus.A.mightgoB.maygoC.couldhavegoneD.oughthavegone6.Weplaychessthanbridge.Someofusdon'tknowhowtoplaybridge.A.hadbetterB.wouldbetterC.wouldratherD.hadrather7.Thereissomeoneknockingatthedoor.itbeTom?A.CanB.MustC.ShouldD.Ought8.Therewasalotoftime.He.A.mustn'thavehurriedB.needn'thavehurriedC.couldhavehurriedD.oughttohavehurried9.Wedidn'tstudyChemistrylastnight,butwe.A.hadstudiedB.couldC.shouldD.couldhave10.Oneoughtforwhatonehasn'tdone.A.nottobepunishedB.tonotbepunishedC.tonotpunishedD.notbepunished11.MayIpickaflowerinthegarden?.A.No,youneedn'tB.Not,pleaseC.No,youmustn'tD.No,youwon't12.CouldIcallyoubyyourfirstname?Yes,you.A.willB.couldC.mayD.might13.Twoyearsago,myhusbandboughtmeabicycle.Ifyouliveintown,itisoftenfasterthanacarandyouworryaboutparking.A.mustnotB.maynotC.shouldnotD.don'thaveto14.Ididn'tseeherinthemeeting-roomthismorning.Sheatthemeeting.A.mustn'thavespokenB.shouldn'thavespokenC.needn'thavespokenD.couldn'thavespoken15.Iwonderhowhethattotheteacher.A.daretosayB.daresayingC.notdaresayD.daredsay16.Youtakeyourumbrella.Iamsureitwon'train.A.shouldn'tB.can'tC.don'thavetoD.mustn't17.Thedoghibernateinwinter.A.don'tneedB.doesn'tneedtoC.needsnottoD.needsnot18.Lookwhatyouhavedone.Youhavebeencareful.A.shouldB.canC.mustD.may19.Tomdidnotgotothepartyyesterday,orIhim.A.wouldseeB.couldmeetC.mighthaveseenD.mightsee20.—Let'sgotothecinema,shallwe?—?A.No,Ican'tB.Yes,IwillC.Yes,thankyouD.No,we'dbetternot21.Ifyouhadbeenmorecareful,youhavemadesomanymistakes.A.won'tB.wouldn'tC