当前位置:首页 > 商业/管理/HR > 资本运营 > 情态动词-专升本英语语法详细讲解课件
助动词动词表示动作形态,但英语里有些动词并不表示动作形态,而是协助主动词表示时态(tenses)或语态(voices)。这些动词叫助动词(auxiliaryverbs)英语中助动词主要有两类:一是基本助动词,如have,do,be;二是半助动词,如beaboutto等三是情态助动词,如may,must,need等。基本助动词助动词可表示动词时态和语态,构成疑问句和否定句,例如“have,has,had”用来构成完成时态;“be,is,are,am,been,was,were,being”构成被动语态Whatdoyoudoeveryday?Bettyhascompletedherworkontime.Jasoniswritinganewbook.Aratwascaughtbyacat.构成疑问句附加语,如:Mr.Chenhasnotbecomeabusinessman,hashe?Jason'slecturesareclearandeasy-to-understand,aren'tthey?构成简短答语,如:-Willyouhelpuswiththegardening?Yes,Iwill./No,Iwon't.-Ihaveseenthatfilmbefore.-SohaveI.-Williamisn'tateacher.-Neitherishiswife.构成省略句,如:Thebossdoesn'toftencometothefactoryandwhenhedoes,itisgenerallyonSunday.半助动词在功能上介乎主动词和助动词之间的一类结构,称为半助动词。常见的半助动词有beaboutto,bedueto,begoingto,belikelyto,bemeantto,beobligedto,besupposedto,bewillingto,haveto,seemto,beunableto,beunwillingto等。它们可与主动词搭配构成复杂动词词组并表示情态意义,有时也可与助动词搭配,例如:HeisunwillingtohelpmewithmyEnglish.Everyclauseisobligedtoobtainafiniteverb.Wewereabouttostartwhenitrained.Heseemstobeverydisappointed.Idon’thavetobuyanewhouse.情态动词情态动词有can(could),may(might),must,need,oughtto,dare(dared),shall(should),will(would).在肯定句中它们后边都要接动词原形.在否定句中,can,may,must和dare后边加not;haveto和oughtto分别在have和ought后加not;hadbetter和wouldrather的否定式分别是hadbetternot和wouldrathernot。这些情态动词与现在完成时连用在某种意义上有一定的虚拟性。情态动词+动词原形情态动词+动词完成式情态动词+动词进行式情态动词+动词完成进行式某些情态动词的特殊用法一、情态动词+动词原形can表示体力或脑力方面的“能力”、“技能”或根据客观条件能做某种动作的“可能性”Mygrandmaisoverseventy,butshecanstillreadwithoutglasses.但表示人体力或智力的具体动作时须用beabletoHewasabletodothatwithoutanyhelp.may表示“允许,可以”,相当于beallowedtoYoumaygonow.MayIuseyourcomputer?may或might可和aswell连用,表示“建议”,译为“还是……的为好”Youmayaswellkeepacertaindistancefromthatmadman.Youmightaswellgohomenow.must表示“必须”或“应当”、“一定”在回答must引起的问题时,如果是否定的答复,不能用mustn’t,而要用needn’t或don’thaveto,因为mustn’t是“一定不要”、“一定不能”的意思。Youmustcometotheclassroombeforeeight.“Mustwedoitnow?”“No,youneedn’t.”haveto加动词原形,表示“不得不”,“必须”,它比must更强调客观haveto可用于多种时态,而must一般用于现在时,其过去时与将来时分别由hadto与shall/willhaveto代替Tomhadtoworkintothedeepnighteverydaytoearnaliving.should表示“劝告”,“建议”或“义务”时,译作“应当”,或表示“预测”和“可能”Heshouldtakecareofhisparentsastheyareoldenoughnottoliveonthemselves.Heshouldbetherenow.shouldhavedone在虚拟语气中表示“责备或后悔ought,只有一种形式,即ought后必须加to,然后跟接动词原形表示“有义务”或“必要”做某事,译为“应当,应该”Yououghtnottomakefunofhim.Heisnottheoneyoulaughatbutlearnfrom.dare作为情态动词时,主要用于疑问句和否定句,表示“敢”,后面跟不带to的动词不定式。如:Howdareshedothingslikethattome?-Dareyoucatchthemouse?Dare也用作实义动词,其后的动词不定式可带to也可不带to,且dare有人称和数以及时态的变化。例如:Idaretojumpdownfromthetopofthewall.Shedoesn'tdare(to)meetherteacher\'seyesneed意为“需要”,既可作情态动词,也可作实义动词.作情态动词无人称或数的变化,后接动词原形,如:Youneedn'tworry.Thepresidentwonderedwhetherheneedsendmoresoldiersneed作为行为动词有人称和数的变化,后面可接名词、代词、动名词及带to的动词不定式;可用于肯定句、疑问句和否定句中,如:Sheneedshelp.Idon‘tneedtoseethedoctor.Doyouneedtogoatonce?will(would)决心,愿望。would为will的过去式,可用于各种人称。I'lldomybesttocatchupwiththem.It'shot.WillyouopenthewindowsWouldyoulikesomecoffee?二.情态动词+动词完成式musthavev-ed表示推测过去某事“一定”发生了。其否定形式为:can’t/couldn’thavev-ed,表示过去不可能发生某事。例如:Sincetheditchisfullofwater,itmusthaverainedlastnight.Youcouldn’thavemetmygrandmother.Shediedbeforeyouwereborn.may(might)+have+ED分词:用于肯定句和否定句,表示对已发生事情的不肯定的推测,相当于“可能,大概,”其中might较may语气更弱,把握更小Shemighthavegonetoseeherdoctorlastweek,butIamnotsureshould(oughtto)+have+ED分词:肯定句表示过去本应发生的事却没有发生;否定句表示已发生了本不该发生的事。前者可译为“本应,”后者为“本不该”YoushouldhaveapologizedtoherfornotsoonreplyingtotheletterYououghtnottomakefunofhim.Heisnottheoneyoulaughatbutlearnfrom.Can/couldhavedone表示假设,与过去的事实相反。推测过去某动作“很可能”发生了.can和could一般用于否定句和疑问句,could的语气较can弱。例如:Hecouldhavebeenveryrich,buthecaredfornomoneyatallHecan'thavefinishedtheworksosoon.needn’t+have+ED分词:表示对过去不必做的事情却做了,可译为“其实不必”Youneedn’thavewakenmeup;Idon’thavetogotoworktoday.表示推测过去某动作发生的可能性时,就表示的可能性程度而言,must最大,could其次,may更次之,might最小。例如:“IwonderhowTomknewaboutyourpast.”“Hemust/could/may/mighthaveheardofitfromMary.”例题:Iwasreallyanxiousaboutyou.You________homewithoutawordA.mustn’thaveB.shouldn’thaveleftC.couldn’thaveleftD.needn’thave三.情态动词+动词进行式情态动词+行为动词进行式(即情态动词+be+v-ing形式),表示推测或评论某动作现在是否正在进行。例如:Hemustbeplayingbasketballintheroom.Shemaybestayingathome.四.情态动词+动词完成进行式情态动词+行为动词完成进行式(即情态动词+havebeen+v-ing形式),表示推测或评论过去某动作是否正在进行或一直在进行。例如:Theyshouldhavebeenmeetingtodiscusstheproblem.Hemay/mighthavebeenbuyingstampsinthepostofficewhenyousawhim.五.用作情态动词的其他短语wouldrather,wouldsooner,would(just)assoon,hadrather,hadbetter,hadsooner,cannotbut,may(just)aswell等可用作情态动词Thesoldierwouldsoonerdiethansurrender.Thebravesoldierwouldassoondieasyieldtosuchanenemy.Ifyoudon’tliketoswim,youmayjustaswellstayathome.这些短语后一般直接跟动词原形.would(had)rather,would(had)sooner,would(just)assoon后可跟that引导的从句,that常省去,从句要用虚拟语气。对现在和将来的假设用过去时,对过去的假设用过去完成时。例如:IwouldratheryoucameonSunday.Iwouldsooneryouhadn’taskedmetospeakyesterday.
本文标题:情态动词-专升本英语语法详细讲解课件
链接地址:https://www.777doc.com/doc-4733418 .html