虚拟语气和情态动词课件

英语语法EnglishGrammar第四章动词和动词词组情态助动词虚拟语气动词词组动词词组是以主动词（又叫实义动词）为中心词的词组，它可以仅由一个主动词构成，这叫做简单动词词组。即：主动词。例如：Hebuyseggseverytimehegoesshopping.（一般现在时）Theworkersreceivedaraiselastyear.（一般过去时）动词词组也可由一个或一个以上的助动词加主动词构成，这叫做复杂动词词组。即：助动词+主动词。例如：Sheisvisitingus.Theyhavebeentakingmusiclessons.Youshouldhavereadthebook.Heneedn’thavebeenwaitingintherain.基本助动词基本助动词只有三个：be，do，have。它们起着语法作用或者说表示语法意义。比如助动词be通常用来协助主动词构成进行体或被动态：Iamlisteningtomusic.Thestudentswerepraisedbytheprincipal（校长）.助动词do通常用来协助主动词表示否定意义或构成疑问句：Mywifedoesn’tknowRussian.WhatdidshegivetoHalleckforhisbirthday?助动词do还可以用来加重语气：Youdolookwell.Hedidannoyeveryonethatevening.助动词have通常用来协助主动词构成完成体或完成进行体：Joanhasseenthatmovie.Ihavebeenworkingherefor20years.提示：如果有多个助动词，第一个助动词体现“时”。半助动词半助动词指某些兼有主动词和助动词特征的语法结构，比如haveto，seemto之类。Ihavetobuyanewcar.Heseemstobedisappointed.Idon’thavetobuyanewcar.Youwillhavetosellyourhouse.情态助动词情态助动词共有13个，其中包括一些过去时形式，它们是can/could，may/might，will/would，shall/should，must，dare，need，oughtto，usedto。情态助动词表示情态意义，其过去时形式并不一定就表示过去时间。情态助动词不能重叠使用；随后的主动词无一例外地是不带to的不定式即动词原形。例如：Itmaysnowbeforenightfall.ShemustknowhowtospeakItalian.Wouldyouletmeuseyourpenaminute?WhenIlivedatDelMar,Iusedto

takealongwalkalongthefootpathunderthepinetrees.情态助动词情态助动词总的来说表达以下意义“可能性”，“频度（will,would,usedto）”“倾向”，“职责”。例如：Whathesaidmaybetrue.他说得话也许是真的。（可能性）Paulinewillworkalldaywithoutarest.Pauline总是能够不用休息整天工作。（频度）Iwillhelpyouifyoulike.如果你愿意，我会帮助你的。（倾向）Youmustcomehereontime.你必须准时来这。（职责）表示将来的“必须”，常用haveto（必须，不得不）的一定形式——will/shallhaveto.Wemustdoitagain.（现在）Wewillhavetodoitagain.（将来）表示过去的“必须”，常用haveto的过去时形式—hadto.Imustleaveatsix.Ihadtoleaveatsixyesterday.Must有两个否定形式：

1.mustn’t表示”不许，禁止”Youmustn’ttalklikethat.2.needn’t表示“不必”-Mustyouleavesosoon?-No,youneedn’t.needn’t=don’thaveto不必，不需要Youdon’t

havetostayathome.Youdon’t

havetokeepthewindowclosed,wearenotcold.can能够（现在或将来的能力），许可Hecanswimacrosstheriver.（能够）

He

can

speakfivelanguages.（能够）-CanIuseyourpen,please?（请求许可）-Yes,youcan.(给予许可)-No,youcan’t.（不许）Youcanplayaroundhere,ifyoulike.（给予许可）如果你喜欢的话，你可以在附近玩。may许可（同can一样）-MayIhavealookatyourphoto,please?

-Yes,please./No,youmaynot.

-MayIaskyouaquestion?

-Yes,youcan/may.You

maygowhicheverwayyoulike.should应该Youshouldfinishyourworkontime.Youshouldn’tbelateforclass.oughtto应该Yououghttofinishyourworkontime.Yououghttoobeyregulations.Heoughttodohisdutywell.will意愿，决心，意图，有礼貌的请求Iwilldothisdifficultjob.（决心）Iwillcallyoutonight.（意愿）

Willyoupleasetellmeyournameandaddress?（有礼貌的请求）willnot(won’t)不愿意，拒绝Iwon’tdoitagain.不愿意Theboywon’tlistentoothers’advice.拒绝=Theboyrefusestolistentoothers’advice.shall和will的区别Shall表示建议，征求对方意见。shall一般用于第一人称，而will一般用于二，三人称。Shallwegotothepark？Willyougowithme?Whatshallwedo?情态动词表示对可能性的推测按其可能性程度的高低排列为：must﹥will﹥would﹥can﹥could﹥may

﹥might

表示对现在情况的推测Hemustbeinhisearlythirties.他肯定（最有可能）三十岁出头。

注意must只能用于肯定句，它的否定形式有两种当must作“必须,有必要”讲时，其否定形式为needn’t。

Must

we

hand

in

our

exercises

today?

我们必须今天交练习吗?No，you

needn't.

不，不必今天交。

MustIbehomebeforenineo’clock?我必须在九点之前赶到家么？No,youneedn’t.

不，不必。当must表示“推测”，作“一定；必定”讲时，其否定形式为can’t。-Itmustbeourheadmaster.

-No.Itcan'tbehim,becausehewenttoLondonthismorning.can/could+不定式完成体这种结构也表示过去可能性的推测：Hecan’t/couldhavebeenhurt.他可能/不可能受伤了。（指说话之前受的伤）Shecan’t/couldhavemissedthetrain.她可能/不可能错过火车。might/could+不定式完成体这种结构还可表示本来可能发生但没有发生，或者本来可能完成却没有完成的动作。Youmighthavekilledyourself.（你本来可能送命的。）Youcouldhavecomeearlier.你本该早些来。（但没能早些来）Hecouldhavedonebetter.他本该做得更好的。（但没能做得更好）Icouldhavereportedyou.（我本可以告发你。）must+不定式完成体1，也表示对过去事态的推测，译为“一定已经”例如：Youmusthaveleftyourhandbaginthetheatre.你一定把你的手提袋落在剧院了。Hereyesarered.Shemusthavebeencrying.她眼睛红红的，一定是哭过。2，表示推测的must的否定形式为can’t而不是mustnot.IfFreddidn’tleavehomebeforefive,hecan’tbethereyet.如果Fred五点之前没从家出发，他可能还没到那。Hecan’thavebeentoyourhome.Hedoesn’tknowyouraddress.他不可能去过你家，他都不知道你的地址。oughtto/should+不定式完成体可表示本来应该做某事却没有做或者本来不该做某事却做了。Youshould/oughttohaveaskedmypermissionfist.你本该事先征得我允许的。Youshouldn’t/oughtn’ttohavebeenrestingatthattimeofday.你那会本不该休息的。还可表示对过去事情的推测，译为“应该已经”。Ithinkheoughttohavearrivedhomebynow.我想他现在应该到家了。练习1Thatmustbeamistake.

No,it_____amistake.

A.mustnotbeB.needn’tbeC.cannotbeD.wouldnotbe

CYou____seeher,butImust.A.haven’tB.cannotC.mustn’tD.needn’tPeter___comewithustonight,butheisn'tverysureyet.

A.mustB.mayC.canD.will

DDMary____beinLondonbecauseIsawherintownjustnow.

A.mustn’tB.isn’tabletoC.maynotD.cannot____tohavelunchwithustoday?

A.DoyoulikeB.WouldyoulikeC.WillyoulikeD.Haveyoulike

DBMr.Smithpromisedtocomeatsix,butitisalreadynine.He____missedthetrain.A.willhaveB.hastohaveC.mayhaveD.oughttohaveAcomputer________thinkforitself;it________betoldwhattodo.A.maynot,mustB.mustn't,might C.shouldn't,couldD.can't,mustCDYouarerunningafever.You____toseethedoctor.A.needgoB.musthavegoneC.shouldgoD.cangoYou_________dotheexerciseifyoudon'twantto.A.maynot B.can't C.mustn'tD.needn'tCD虚拟语气英语动词在一定的语境中可以表达不同的语气，以表明说话人的态度。语气大概可分为三种：陈述语气，祈使语气和虚拟语气。虚拟语气分为两种形式：从句动词用过去时态；从句动词用should+动词原形，其中should可以省略。从句动词用should+动词原形这种虚拟式指不管主语是什么人称，动词一律为原形。这种虚拟式主要用于某些表示建议、要求、决定、意图、需要等主动词所带的宾语从句中，有advise,order,insist,suggest,demand,request等，要求用“should+动词原形”或只用动词原形。Isuggestthathe(should)beleaderoftheteam.ThedoctoradvisedthatItakemoreexercisesandwatchlessTV.MytutorinsistedthatIwriteanessayinthisway.Theyorderthathedoithimself.虚拟语气用于宾语从句这种虚拟式还可用于与上述动词同形的名词（desire,advice,demand,order,request，suggestion等）以及proposal,decision,plan,idea等后面的表语从句或同位语从句中，要求用“should+动词原形”或只用动词原形。Thedoctor’sadviceisthatheshouldgiveupsmoking.Thepolice’sorderwasthatallthepeopleleavethebuilding.用于同位语从句和表语从句中这种虚拟式还可用于某些表示建议，要求，需要等形容词词组中的that所引导的分句中。这些形容词有：essential,important,necessary，desirable，urgent等，谓语动词用should+动词原形。Itisnecessarythatheseehisdoctoronceaweek.Itisimportantthatthechildrenhaveagoodeducation.虚拟语气用于主语从句中过去时态的虚拟式指不管主语是什么人称，动词一律用were。在Iwish后的that分句中。

S+wish+(that)+S+were…IwishIwereabird,andIwouldbeflyinginthesky.IwishIwereyou.S+wish+(that)+S+did….

IwishIhadwings.(Infact,Idon’thavewings)Iwishshestayedwithusnow.(Infact,shedoesn’tstaywithus)ShewishesthatIdidn’tlikeplayingcomputergames.(Infact,Ilikeit)S+wish+(that)+S+haddone….

IwishIhadwashedtheclothesyesterday.(Infact,Ididn’twashtheclothes.)Theboywishesthathehadn’ttoldalielastweek.(Infact,theboytoldthelielastweek.)ShewishesshehadbeentotheGreatWallbefore.(Infact,shehasneverbeentotheGreatWall)还用于由if,ifonly,asif/though,though,等引导的条件状语或让步状语分句中，表示非真实的条件或让步IfonlyIwereabird!如果我是只鸟那该多好啊！IfonlyIknewfivelanguages!如果我懂五国语言那该多好！IfonlyIhadbeentotheGreatWall!如果我去过长城那该多好！IfonlyIhadn’tmadethemistakeyesterday!如果我昨天没犯错那该多好！与现在事实相反的假设If+主语+过去式,主语+would+原形couldmightIfhewereyou,hewouldbeangry.Ifhehadwings,hewouldfly.Iftherewerenosun,nothingcouldlive.与过去事实相反的假设：If+主语+过去完成体,主语+should/+have+过去分词couldwouldmightIfhehadhadmoney,hewouldhavegoneabroadlastyear.IfIhadbeenyou,Iwouldhavebeenangryyesterday.Ifhehadworkedharder,hewouldnothavefailed.与将来事实相反的假设：If+主语+过去式或wereto,主语+would+原型shouldmightcould

IfIweretodietoday,myfamilywouldstarvetomorrow.Whatwouldhappenifweweretolosethesecretofmakingfire?Ilostmywatchyesterday.IfonlyI_____it!A.hadn’tlost B.haven’tlost C.didn’tlose D.don’tloseYou____suchaseriousmistakeifyouhadfollowedhisadvice.A.maynotmake B.mightnotmakeC.shouldn’thavemadeD.wouldnothavemadeAD练习2Theteacherdemandedthattheexam_____beforeeleven.A.mustfinish B.wouldbefinished C.befinishedD.mustbefinishedCMr.Greenrequiresthatthestudents___compositioneveryotherweek.

A.writeB.writtenC.wouldwriteD.willwrite

AIwishI___whatishappeningthereinhisroom.

A.knowB.isknownC.knewD.shouldknowItisimportantthathe___sportseveryday.

A.haveB.wouldhaveC.musthaveD.willhave

CAMrs.Blackinsists___inthatoldhotel.

A.nottostayB.notstayingC.she