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1、Unit1LearningaboutlanguageGrammarLearningaims1.Tocontinuetolearnmodalverbs.2.Tolearnitsusages.3.Tobeabletoputthemintopractice.情态动词ModalVerb情态动词有一定的意义，但没有人称和数的变化，不能独立使用，它和后面的动词构成谓语．除ought和have外，后面只能接不带to的不定式。只作情态动词的can/could,may/might,oughtto,must可情态可实义的need,dare可
2、情态可助动词的shall/should,will/would相当于情态动词的haveto,hadbetter情态动词含义否定式注意点can/could表能力“能，会”can’t“不会，不能”区别beableto表许可“可以”can’t“不可以，不许”代替may表推测“可能”can’t“不可能”主要用于否定、疑问句中1表示某人通过努力克服困难做成某事,要用was/wereableto.2could,might,would表委婉语气用于疑问句,答语仍须用can,may,will.3can用于肯定句中,可表示”有时可能”---
3、MayIuseyourpencil?---Yes,youmay./No,youmustn’t.Shemaynotbeworkingnow.Johnmightbeathomenow.Helenmaygoonthetripwithus,butsheisn’tverysureyet.Shemay/mighthavereaditinthepaper.Hemaynothavefinishedreadingthebook.情态动词含义否定式注意点may/might表许可“可以”mustn’t“不许，严禁”口语中也可用can’t表推测
4、“可能”Maynot“可能不”主要用于肯定句，不能用在疑问句（maynot可能不）IfyouwillhelpmewithmyEnglish,Iwillbeveryhappy.IpromisedthatIwoulddomybest.Willyoutellmesomethingaboutyourhometown?Wouldyoupleasespeakagainmoreslowly？Hewillalwaystakeawalkaftersupper.Duringthevacationhewouldoftenvisitme.情态动
5、词用法will表请求(第二人称)表意志,意愿表某种倾向或习惯would更客气的请求过去的意志,意愿过去的倾向或习惯Shallwesetoffnow?YoushalldoasIsay.Tellhimthatheshallhavethebooktomorrow.Youshallbepunishedifyoudothatagain.Youshouldn’t/oughtn’ttosmokesomuch.Sheshouldn’thaveleftwithoutsayingaword.It’sfiveo’clock.Johnshoul
6、dbeathomenow.Wehavepreparedafridgeoffoodanddrinks.Thatoughttobeenoughfortheparty.It’sapitythatheshouldbesorudetoalady.情态动词用法shall征求对方意见(第一,三人称)表示命令,警告,威胁或允诺(第二,三人称)should/oughtto表示劝告,建议,命令或责任“应该,必须”表示推测,“理应,估计,大概,可望”should还可表示“竟然”---MustI finish all assignments a
7、t a time?---Yes,youmust./No, youneedn't.Idon’tlikethisTVset.Wemustbuyanewone.Therewasnomorebus.Theyhadtowalkhome.Youmustbe the new teacher.There is nobody here. Theymust have allgonehome.MyMP4isn’tinmybag.WherecanIhaveputit?John,lookatthetime.Mustyouplaythepianoa
8、tsuchalatehour?情态动词含义否定式注意点must表必要“必须”needn’t“不必”(区别haveto)有时表“偏要”表推测“一定”can’t“不可能”只能用于肯定句，不能用于否定、疑问句1.Acomputer______thinkforitself;itmustbetoldwhattodo.A.can
