情态动词

•动词四类•1.实义动词（99%）•2.系动词•3.情态动词•4.助动词•动词四类•1.实义动词（99%）•2.系动词•3.情态动词•4.助动词Exercise•我们必须输！•我们输的起！•我们可能会输的！Wemustlose!Wemaylose!Wecanlose!CanIuseyourphoneplease?CouldIuseyourphoneplease?MayIuseyourphoneplease?MightIuseyourphoneplease?委婉直截了当尊重委婉礼貌客气尊重委婉（虚礼）CanMayCouldMight•情态动词不能单独作谓语，只能和其他动词（包括动词原形及其被动语态）一起构成谓语，表示说话人对有关行为或事物的态度和看法。•情态动词本身有一定意义，一般没有人称和数的变化。一、情态动词定义？二、情态动词的用法•(1)表能力，一般翻译成“能”，可用beableto代替•e.g.Ithinkwecancompletetheworkaheadoftime.•I'llnotbeabletocomethisafternoon.二、情态动词的用法•(2)表客观可能性，在疑问句中表示请求或许可•e.g.Mancannotlivewithoutair.•CanIuseyourpen?•*could是can的过去时，主要用于疑问句，表示语气委婉。•肯定回答用•否定回答可用•e.g.——CouldIcometoseeyoutomorrow?•——Yes,youcan.•——No,I'mafraidnot.canNo,I'mafraidnot.二、情态动词的用法•(3)表惊异、怀疑、不相信的态度（主要用在否定句、疑问句或感叹句中）•e.g.Canthisbetrue?•Howcanyoubesocareless!•Hecan'tbethere!•——CouldIborrowyourumbrella,please?•——I',afraidyou_____.•A.couldB.canC.couldn'tD.can't二、情态动词的用法(1)表许可，使用might时，表示语气较委婉。可以指过去的时间，也可指现在的时间。•e.g.Youmaytakewhateveryoulike.•May(Might)Iaskforaphotoofyourbaby?2.may和might二、情态动词的用法(1)用于祈使句中表祝愿。•e.g.Mayyousucceed!2.may和might•Lookout!Theknifeisverysharp.You____cutyourfinger.•A.needB.must•C.shouldD.may二、情态动词的用法(1)must表义务或强制。译为“必须”，多强调意志。•e.g.Wemustrespectourteachersandparents.•Imustdomyhomeworkeveryday.表义务表强制3.must和haveto•*回答以must引出的问句时，•肯定回答用•否定回答可用•e.g.——Mustwehandinourexercisebooksnow?•——Yes,youmust.•——No,youneedn't/No,youdon'thaveto.mustneedn't或don'thaveto二、情态动词的用法(2)haveto的含义与must相似，但的变化，多强调必要性。•e.g.It'stoolate,andhehastogo.•IhadtoworkwhenIwasyourage.3.must和haveto•Myparentsneverremembermytelephonenumber,andtheyalways____lookitup.•A.mustB.can•C.shouldD.haveto二、情态动词的用法•need“需要”dare“敢”可作情态动词也可作实义动词(1)当情态动词使用时，无人称和时态的变化，主要用于疑问句和否定句•e.g.——NeedIfinishtheworktoday?•——Yes,youmust.•HowdareyousayI'munfair?4.dare和need二、情态动词的用法need“需要”dare“敢”可作情态动词也可作实义动词•(2)当实义动词使用时，有人称和时态的变化•e.g.Youdon'tneedtodoityourself.•Hedidnotdare(to)lookup.4.dare和need•——Canyoudriveacaratpresent?•——I_____dosointhebusystreet.•A.maynotB.don'tdareC.daren'tD.needn't二、情态动词的用法•(1)usedto表示过去的习惯动作或状态，现已不存在。•e.g.Thereusedtobeourplayground.5.usedto和hadbetter二、情态动词的用法(2)hadbetter意为“最好”。•e.g.Wehadbetter(not）gonow.5.usedto和hadbetter二、情态动词的用法(1)should表“应该”，用法类似的有oughtto.•e.g.Youshould(oughtto)gotoclassrightaway.•在疑问句中通常用should代替oughtto。•ShouldIopenthewindow？6.should和oughtto二、情态动词的用法(2)shouldhavedone表应该做到而没做到，并包含一种埋怨、责备的口气。•e.g.Ishouldhelpedher,butInevercould.6.should和oughtto•You_____himthetruth.•A.shallhavetoldB.shalltellC.shouldtellD.shouldhavetold二、情态动词的用法(1)表意愿，用于各种人称的陈述句。•e.g.Iwilldoanythingforyou.•Ifyouwillreadthebook,I'lllendittoyou.7.will和would二、情态动词的用法(2)表请求、建议等，用于疑问句，would比will更委婉。•e.g.Willyouclosethewindow?•Wouldyoupassmethebook?7.will和would二、情态动词的用法(1)表对现在或将来发生的事情的推测，肯定用mustbe，否定用Can'tbe。•e.g.ThismustbeBill'sbed,it'ssotidy.•Thiscan'tbeBill'sbed,it'ssotidy.8.情态动词可表推测二、情态动词的用法•(2)表对过去行为或动作进行推测，•肯定用musthavedone，•否定用can(could)nothavedone.•e.g.Sincethegroundiswet,itmusthaverainedlastnight.•Hetheway,Idrewhimamap.8.情态动词可表推测•Tom_____beadoctor,forheworksinabookshtore.•A.needn’tB.can’t•C.shouldD.may•——I’msorry.I____atyoutheotherday.•——Forgetit.Iwasabitofcontrolmyself.•A.shouldn’tshoutB.shouldn’thaveshoutedC.mustn’tshoutD.mustn’thaveshouted