(完整PPT)高一英语英语必修3Unit1语法课件.ppt

ModalVerbIHemusthavegonetoBeijing.2.Thedoorwaslocked.Shecouldn’thavebeenathome.3.Theymaybestillwaitingforus.4.Hemighthavereadaboutthenewsinthenewspaper.5.Youshouldhavetoldhimaweekago.6.Canyougivemesomesuggestions?7.Theywantedtoknowwhenyouwouldgotothepark.情态动词表示说话人的某种感情或语气，对某一动作或状态的某种态度。表示“需要、可以、必须、应当”等。Wordslikecan,will,may,must,andafewothersarecalledmodals.Modalverbshelpotherverbsexpressameaningoranidea.Somecommonusesofthemodalsarethese:Ability:1HecanspeakEnglishnow.2Hecouldn’tspeakEnglishayearago.3I’mnotabletocometothegameonFriday.Permission:Allpassengersmaynowboard.Wecanboardnow.Obligation:Youmustfastenyourseatbelts.(strong)Youshouldpayattention.(weak)Yououghttopayattention.Possibility:1Itmayrain.2HowcouldIforgetanimportantthinglikethat?3Hecan’t/couldn’thaveknowntheresult.Meaningssimilartothoseofthemodalscanoftenbeconveyedbyrealverbforms:Hehasto……………………….=…must…isableto…speakEnglish…=…can…isallowedto……………....=…may…issupposedto……………=…should…情态动词的语法特征只作情态动词的can/could,may/might,oughtto,must可情态可实义的need,dare/dared可情态可助动词的shall/should,will/would相当于情态动词的haveto,usedto1.can的主要用法是：A.表示体力或脑力的能力：eg.Thegirlcandanceverywell.B.表示说话者的推测﹑事物的可能性:eg.Canthenewsbetrue?C.在口语中,can可以表示请求或允许：eg.CanIsithere?2.could的主要用法是：A.could是can的过去式,表示与过去有关的能力和推测:eg.Weallknewthattheyoungmancouldn’tbeadoctor.B.could可以代替can表示请求,但语气较can客气、委婉:eg.Couldyoulendmeyourdictionary?CouldIuseyourbike?3.can和could接动词的完成形式，表示可能已经做某事。can用在否定和疑问句中,表示不相信、怀疑等态度。eg.Theycan'thavegoneoutbecausethelightisstillon.may常用来表示：A.表示请求、允许：比can较为正式:eg.MayIcomein?Youmaygonow.B.表示说话人的猜测:“也许”“可能”:通常只用于肯定句和否定句中。eg.--IbelievethemanisfromEngland.--ButImaybewrong.Theguestmayarrivethisafternoon.在肯定句中，may的可能性比can高，may表示现实的可能性，can表示理论上的可能性。如：Theroadmaybeblocked.这条路可能不通了。Theroadcanbeblocked.这条路可能会是不通的。在疑问句中，表示可能性用can。如：Wherecanhebe?他会在哪呢？C.表示祝愿;但语气较正式:eg.Mayyousucceed!Mayyouhaveagoodjourney!might的用法有:多在间接引语中表示过去的可能和允许。如:Shesaidthathemighttakeherbike.她说他可以拿她的自行车去用。除了在间接引语中以外，might一般不表示过去的可能或者许可。如要表示过去的可能可以用could,表示过去的许可可以用was(were)allowedto或者had