高中英语必修四五单元GrammarPPT课件

.,1,Revisionofmodalverbs情态动词,Module5,.,2,1.can-could表示能力,可能性表示许可、请求,常译为“可以”表示说话人的猜测，用来表达惊异、怀疑、不相信等态度，主要用于疑问句和否定句,IcanspeakEnglish.Hecouldwritemusicwhenhewasfour.,与过去有关的能力,更客气、委婉,惊异,怀疑,不可能、不相信,CanIuseyourdictionary?CouldIseeyourpassport?,Ibelieveher.Shecantbesuchagirl.Whatcanthechildrenbedoing?Thegroundisntwet.Itcanthaverainedlastnight.,.,3,注意can与beableto的区别a.can常指现在,beableto用于多种时态。Theywillbeabletotellyouthenewssoon.b.过去式含义不同：was/wereableto设法做成某事(managedtodosth./succeededindoingsth.)could仅表示有可能、能够做某事,事实上不一定去做。Mostpeoplewereabletoescapefromtheburningbuilding.ImafraidIcouldntarriveontime.,.,4,2.must表示“必须，应该”否定回答时常用neednt或donthaveto.MustIgothereinperson?我必须亲自去吗？WemustalwaysfollowtheParty.我们要永远跟着党走。表示“必然”Allmenmustdie.人总是要死的。表示推测，“准是”、“一定”，否定形式为cantShemustbeathomenow.她现在准在家。Hemusthavetoldyouthatyesterday.昨天他一定已经告诉你了,.,5,注意must与haveto的区别,1.haveto表示由于客观因素不得不做must表示说话人的主观意志,看法,e.g.Wemusthandinourpaperstoday.今天我们必须把卷子交上去。（主观看法）e.g.Wehavetogettherebeforedark.天黑前我们必须到达那里。（客观需要）,2.haveto有人称、数、时态的变化，而must只有一种形式。,e.g.Hehadtolookafterhissisteryesterday.,.,6,3.否定结构中donthaveto表示“不必”mustnt表示“禁止”。,e.g.Youdonthavetotellhimaboutit.你没必要把此事告诉他。,e.g.Youmustnttellhimaboutit.你一定不要把这件事告诉他。,.,7,3.may-might许可，可以e.g.Youmayborrowthebacknumbers.你可以借过期期刊。MayIcomein?MightIgotothehospitaltoseemyfather?否定形式为maynot,但表示“不可以”或“禁止”时用mustnot(mustnt).e.g.ayIwatchTVnow?我现在可以看电视吗？o,youmustnt.不，你不可以看。may,might还可以表示推测,但might可能性比may小。e.g.Theremaybeafewcopiesleftinthebookstore.书店里可能还有几本书。Theymighthavebeenkilledbyradiation.may放在句首,表示祝愿。e.g.MayGodblessyou!,征询对方许可,更委婉,或许，很不确定,.,8,Peter_comewithustonight,butheisntverysureyet.A.mustB.mayC.canD.will,答案B.表可能性只能用may。此句意可从后半句推出。,.,9,should应该；oughtto义务，责任，语气稍重一些。e.g.Youshouldkeepyourpromise.你应该遵守你的诺言。Weoughttohelpthemwhentheyareintrouble.当他们有麻烦时，我们有责任帮助他们。,should和oughtto都为“应该”的意思，可用于各种人称。,4.should和oughtto,oughtto着重表示客观要求,含有法律上或道义上的责任。should往往表示说话者的主观意见,表示一种必要性。,Oughthetogo?Yes.Ithinkheoughtto.,.,10,LetsdosomeexercisesinourbooksonPages44!,.,11,表示否定的情态动词的用法:,mustnt不准；禁止neednt没必要(=donthaveto)cant不能；不可能maynot不可以；可能不shouldnt不应该(=oughtnotto),.,12,情态动词表推测,1.情态动词+v./be对现在或将来的推测,Idontknowwheresheis,shemaybeinWuhan.,.,13,2.情态动词+be+v-ing对现在或将来正在进行的情况进行推测,Atthismoment,ourteachermustbecorrectingourexampapers.,.,14,3.情态动词+have+v-ed对过去情况的推测。,Philipmay(might/can/could)havebeenhurtseriouslyinthecaraccident.,4.情态动词+havebeen+v-ing对过去正在发生事情的推测。,Yourmothermusthavebeenlookingforyou.,.,15,Heisathome.(事实)Hemustbeathome.（非常肯定的推断）Hecouldbeathome.（很可能）Heoughttobeathome.（很可能）Hemaybeathome.（仅仅可能而已）Hemightbeathome.（或许,非常不确定）,情态动词表推测时的不同的“肯定”程度：,.,16,Hemightnotbeathome.（也许不在家）Hemaynotbeathome.（比might可能）Hecouldntbeathome.（很可能不在家）Hecantbeathome.（一定不在家）Heisntathome.（事实）,.,17,1.CouldIborrowyourdictionary?Yes,ofcourse,you_.A.mightB.willC.canD.should,答案Ccould表示委婉的语气，并不为时态。答语中ofcourse，表示肯定的语气，允许某人做某事时，用can和may来表达，不能用could或might。,练习,.,18,2.ShallItellJohnaboutit?No,you_.Ivetoldhimalready.A.needntB.wouldntC.mustntD.shouldnt,答案Aneednt不必，不用。wouldnt将不,不会的。mustnt禁止、不能。shouldnt不应该。本题为不需要，不必的意思，应用neednt。,.,19,3.Dontforgettocometomybirthdaypartytomorrow._.A.IdontB.IwontC.IcantD.Ihavent,答案Bwill既可当作情态动词，表请求、建议、也可作为实义动词表“意愿、意志、决心”，本题表示决心，选B。,.,20,4.Tomoughtnotto_meyoursecret,buthemeantnoharm.A.havetoldB.tellC.betellingD.havingtold,答案A由于后句为过去时，告诉秘密的动作又发生在其前因，此地应用过去完成时，但它在情态动词oughtto后，所以用have。,.,21,1.We_haveprovedgreatadventures,butwehavedonethegreatestmarchevermadeinthepasttenyears.(2006天津)A.needntB.maynotC.shouldntD.mustnt,高考链接,.,22,2.Blackholes_notbeseendirectly,sodeterminingthenumberofthemisatoughtask.(2006上海)A.canB.shouldC.mustD.need,.,23,3.Someaspectsofapilotsjob_beboring,andpilotsoften_workatinconvenienthours.(2006湖南)A.can;havetoB.may;canC.haveto;mayD.oughtto;must,.,24,4.Asyouworkedlateyesterday,you_havecomethismorning.(2006陕西)A.mayntB.cantC.mustntD.neednt,.,25,5.Shelooksveryhappy.She_havepassedtheexam.Iguessso.Itsnotdifficultafterall.(2007江苏)A.shouldB.couldC.mustD.might,.,26,6.一Whatdoesthesignoverthereread?一“Noperson_smokeorcarryalightedcigarette,cigarorpipein