英语情态动词讲解.ppt

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1、情态动词ModalVerbs情态动词是什么？动词类别系动词情态动词助动词行为动词能独立做谓语不能独立做谓语情态动词是什么？必须要和其他动词连用；可表示说话人的语气，用来表达建议、要求、可能和意愿等；没有人称和数的变化。常用情态动词现在式can——过去式could（能，可能）现在式may——过去式might（可以）现在式shall——过去式should（应该）现在式will——过去式would（会，将要）must无时态之分hadbetter、dare、need、oughtto情态动词can/could1.can表现在的能力I

2、canswim,butmysistercan't.2.could表过去的能力Atthattimewethoughtthestorycouldnotbetrue.3.Youcannotsmokeinthemeetingroom.(此句的cannot表示“禁止”)情态动词can/could3.can/could与beableto相比beableto可用于各种时态，表能力，强调成功地做某事was/wereableto:设法做成某事相当于managedtodosthsuceededindoingsth情态动词may/might1.

3、may表示请求别人允许e.g.MayIuseyourbike?2.may/might表示可能性e.g.Hemaybeateacher.3.may用于表示,应该(多用于法律条文）e.g.Paymentmaybepaidbycheck.情态动词shall/should1.用于第一、三人称，征求对方意见e.g.Shallwegonow?Whatshouldwedonext?(用should比shall表示更客气)2.shall用于法律、规定，表示义务和规定8.g.Thesignreads:Nopersonshallsmokehe

4、re!3.should表示应该e.g.Youshouldnotjudgeamanbyhisclothes.情态动词will/would1.用于向第二人称征求对方意见(would比will更客气)e.g.Wouldyoupleaseopenthedoor?2.will表示个人主观意愿e.g.Iwillhelpyouanytime.3.would“表过去常常”e.g.Whenhewasthere,hewouldgotothatcoffeeshopeveryday.注：usedtodo“过去常常，强调现在不了”情态动词must1

5、.must表必须e.g.Youmustkeeptheplaceclean.(务必)mustn't禁止e.g.WhenIwasyoung,IwastoldthatImustn'tplaywithfire.2.must还可表示“偏偏，偏要”e.g.Mustyoumakesomuchnoise?情态动词must/haveto1.must表示主观意愿，否定句用mustn’t，否定回答用needn’te.g.Youmustn’tplayinthestreet.－MustIcleantheroomnow?－No,youneedn’t.

6、2.haveto表示客观条件的限制的“不得不”，它有时态和人称变化，需要助动词来否定和疑问。e.g.Idon’thavetocarrythebigbox.Hehadtowashhisclothes.情态动词表推测可能性的强弱层次must＞should/oughtto＞can/could＞may/might1.should/oughtto表示推测根据经验的推测，“应当、应该”e.g.Yourphotosshouldbereadyby12:00.表示“竟然”，带有感情色彩e.g.Itisincrediblethatyous

7、houldlikehim.can/could表推测1.常用于否定句和疑问句e.g.Hecan'tbeathome.(否定句)Canthenewsbetrue?(疑问句)2.can用于肯定句中表示理论上的可能性，并不涉及是否真的会发生e.g.Youcanhurtyourselfifyouplayinthestreet.may/might表推测1.maywell”极有可能”e.g.Lizamaywellnotwanttogoonthetrip,becauseshedislikestravelling.2.may/mightas

8、well”不妨”e.g.Youmayaswelltrytodoit.can?may?must?could?might?1.Jim___can____singverywell.2.Hello,___may/might___IspeaktoJim?3.Wearestudents.We_must__workh