情态动词完成时的用法

情态动词完成时的用法1、语法特点：英语中的情态动词既没有人称的变化，也没有数的变化，但有时态的变化。常见的时态主要有一般式、过去式、进行式和完成式。其中完成时是较难的一种时态形式，其动作主要表过去的行为，它的结构是“情态动词+have+过去分词”，每个情态动词的完成时的含义不同。例如：1)Lastnighthemusthavebeenout,forthelightinhisroomwasnoton.昨晚，他一定出去了，因为他房间里没亮灯。2)Youshouldn’thavebeatenhim.Afterallheisachild.你不应该打他，他毕竟还是个孩子。3)Hemay/mighthavereadthebook.他或许读过那本书了。2、用法归纳：1)must+havedone：用于肯定句，表示推测，意为“一定(已经)……”。例如：Youmusthavemistakenmyintention.你一定是误会了我的意图。2)can+havedone：用于否定句或疑问句，表示推测，意为“可能(已经)……”。例如：Hecan’thaveleftsosoon.他不可能走得这么早。3)could+havedone：可用于肯定句、否定句或疑问句，表示推测、责备或遗憾等，意为“可能……”、“本来可以……”、“本来应该……”等。例如：Wecouldhavewalkedtothestation,foritwassonear.我们本来是可以走到车站去的，因为路很近。4)should[oughtto]+havedone：可用于肯定句、否定句或疑问句，表示责备或遗憾等，意为“本来应该……”。例如：(1)Youshould/oughttohavestartedearlier,butyoudidn”t.你本应该早一点出发，但是你没有。(2)Weshouldn’t/oughtnottohavewaitedforherbecauseshenevercame.我们本不应该等她，因为她根本不会来。5)need+havedone：用于否定句或疑问句，用于否定时意为“本来不必”，用于疑问句时意为“有必要……吗?”。例如：Youneedn’thavetoldhimthenews.他本来不必把这个消息告诉他。6)may+havedone：用于肯定句或否定句，表示推测，意为“可能(已经)……”。例如：Ifwehadtakentheotherroad,wemayhavearrivedearlier.如果我们选择另一条路，我们可能会到得早一些。7)might+havedone：用于肯定句或否定句，表示推测，意为“可能(已经)……(此时might可换为may)；另外还可以表示过来可能发生的事结果未发生，意为“本来会……”(此时might不能换为may)。例如：Imighthavecometoawrongconclusion.我或许得出了错误的结论。二、巩固提高I.Fillintheblanks,usingthepropermodalverbsneedn’t,would,May,mustn’t,won’t.1.—Don’tforgettobringmynewbooktometomorrowafternoon.—No,I_________.2.—Ihearyou’vegotasetofAustraliancoins.________Ihavealook?—Yes,certainly.3.Heseldomlistenstoothers.He_________answerforwhathehasdone.4.—MayIleavetheofficebefore5o’clockintheafternoon?—No,I’mafraidyou_________.5.—ShallItellJohnaboutit?—No,you________.Idon’tknowII.TranslatethefollowingintoEnglish,usingtheperfecttensesofthemodalverbs.1.他不可能离开得这么早。__________________________________________________________________.2.我本应想到这一点的。__________________________________________________________________.3.你没有必要提及此事的。__________________________________________________________________.4.你准是错拿了我的雨伞。__________________________________________________________________.5.我本不应该像那样对我父亲说话的。__________________________________________________________________.III.Choosethebestanswer.()1.Hedoesn'thavetoworktomorrow,butyouhavegotto,________you?A.don'tB.haven'tC.haven'tgotD.can't()2.You________wakemeupwhenIfallasleep,________you?A.haven'tbetter;haveB.wouldnotrather;wouldC.hadbetternot;shouldD.hadnotbetter;must()3.--Why!Icouldn'tgetyouonthephonethismorning.--We________tennisintheyardwhenyouphonedme.A.couldbeplayingB.mustbeplayingC.musthavebeenplayingD.shouldhaveplayed()4.--Wedidn'tseehimatthelecture.--Neitherdidanybodyelse.He________it.A.maynothaveattendedB.mustn'tattendC.can'thaveattendedD.couldn'tattend()5.--Icameherebytaxiandthedriverchargedme50yuan.--Really?You________havecomebybus.A.couldB.mustC.mayD.should()6.--DoyoustillrememberwhenwewenttotheGreatWall?--Ican'trememberitwell,but________ithavebeensometimelastMay?A.shouldB.mustC.couldD.would()7.--IwonderwhyMrLindidn'tcometowork.--He________havebeenill.A.needn'tB.shouldC.mightD.can()8.--Noonepassedthemathematicsexaminationtoday.--Iguesswe________theexerciseslastnight.A.couldreviewB.shouldreviewC.mightreviewD.shouldhavereviewed()9.She________thehospitalsosoon,forshehasn'tyetrecovered.A.wouldn'thaveleftB.shouldn'thaveleftC.needn'tleaveD.hadn'tleft()10.Whydidn'tyoutellmetherewasnomeetingtoday?I________allthewayherethroughtheheavysnow.A.needn'thavedrivenB.can'thavedrivenC.musthavedrivenD.shouldn'thavedriven三、真题零距离()1.--Sorry,ProfessorSmith.Ididn'tfinishtheassignmentyesterday.(2010·上海)--Oh,youhavedoneitasyesterdaywasthedeadline.A.mustB.mustn'tC.shouldD.shouldn't()2.Mark_______havehurried.Afterdrivingattopspeed,hearrivedhalfanhourearly.(2010·天津)A.needn’tB.wouldn’tC.mustn’tD.couldn’t()3.I_______havewatchedthatmovie—it’llgivemehorribledreams.(2010·山东)A.shouldn’tB.needn’tC.couldn’tD.mustn’t