初中情态动词讲解

Learninggoals:复习部分情态动词的用法12情态动词的新用法—情态动词表示推测3对物品的归属进行猜测思考？你记得学过哪些主要的情态动词吗？12情态动词有哪些语法特征呢？can.could,may,must，might,haveto…3情态动词如何使用呢？1.情态动词有具体的词义。2.情态动词没有人称和数的变化。3.情态动词后必须跟动词原形，两者一起构成谓语动词。4.一般疑问句提前边，否定句在后直接加not.can/cannot1.表示能力(会)1)MarycanspeakEnglish,butshecannotspeakFrench.2)Canyouliftthisheavybox?3)Canyouskate?2.表示允许(可以)1）CanIuseyourdictionary?2）-----CanIgohomenow?-----Yes,youcan./No,youcan’t.1.是can的过去式；表示过去的能力；Hecouldrideabikeattheageoffive.2.用于婉转语气,多用于问句。“能，可以”Couldyoupleasecleantheroom?----CouldIcometoseeyoutomorrow?----Yes,youcan.(No,youcan’t.)此处could不是过去式，只是语气更委婉，答语中不能用could和couldn’t，要用can和can’t。couldmay/maynot1.表示请求和允许(可以),比can正式.MayIcomein?Hemaycomeifhelikes.may的用法:may/maynotmay的一般疑问句，其否定回答用can’t或mustn’t。1.--MayIgohomenow?--Yes,youmay./Sure./Yes,please.No,youcan’t./mustn’t.2.--MayIuseyourwashroomnow?--No,you______.There’ssomethingwrongwiththetoilet.A.needn’tB.mustn’tC.shouldn’tD.didn’tBmust/mustnotmust必须,表示说话人的主观意志。Youmustdoyourhomeworkfirst.must的用法:must/mustnotmustn’t表示禁止，不准，不允许。Youmustn’tsmokehere.Youmustn’tplaywithfire.mustnot的用法:must/mustnot以must开头的疑问句，肯定回答：Yes,…must.否定回答:No,…needn’t.或No,…don’thaveto.--MustIcleantheclassroomnow?--Yes,you_______.--No,you_________./No,you____________.mustneedn’tdon’thavetoneed作情态动词，主要用于疑问句和否定句中need一般疑问句:肯定回答用Yes,…must，否定回答用No,…needn’t.或No,…don’thaveto.如：NeedIdoitnow?Yes,you________。No,you___________________.need作行为动词，有人称、数和时态的变化后接todo，即needtodosth.needmustneedn’t/don’thavetomight/maymight1.是may的过去式。2.表示推测,可能性较小。1)Hemightbeverybusynow.2)Yourmothermightknowthetruth.may也表示猜测，意为“可能”。3)WhereismyEnglishbook?Itmight/maybeinyourdesk.Ⅰ.用适当的情态动词填空：1.Icanplayfootball.__________youswim?2.Ican’tplaywithyou.I__________finishmyhomeworkfirst.3.I__________getupearlytomorrow.becauseIhaveameeting.4.Nobody___________livewithoutair.Canmustmustcan5.__________Icomein?Yes,please.6.__________youpleasetellmewherethestationis?7.MustIfinishtheworknow?No,you___________.8.--NeedItakethisbookout?--Yes,you_____.A.canB.mayC.needD.must9.______thegirlreadbeforeshewenttoschool?A.CanB.MustC.CanD.CouldMayCouldneedn’tDDWhosedogisthis?Itmight/couldbe____.Heisasingerandactor,heisknownbyeveryone.Whosedogisthis?ItmustbeLiuDehua’s.Itmight/couldbe____.Heisasingerandactor,heisknownbyeveryone.Anactor,heistall,coolandpopular.Whosedogisthis?Itmight/couldbe___.Anactor,heistall,coolandpopular.Whosedogisthis?Itmight/couldbe___.ItmustbeZhangHan’s.Heisabasketballplayer.Whosecaristhis?Itmight/couldbe__.Heisabasketballplayer.Whosecaristhis?Itmight/couldbe__.Itmustbe_________.Itcan’tbe_________.mineYaoMing’sHeisrichbuthelpful.Whosecaristhis?Itmight/couldbe_____.Itcan’tbe_______.Itmustbe_________.Heisrichbuthelpful.Whosecaristhis?Itmight/couldbe_____.Itcan’tbe_______.Imustbe________.mineBillGates’情态动词表推测讲解must表示推测must表示非常肯定的或有把握的推测，意为“一定，必定”。只用在肯定句中，不能用于否定句中。Eg.Youhaveworkedhardallday.Youmustbetired.might,could表示推测语气更委婉，表示的可能性较小，说话中留有余地，意为“可能，也许，或许”。1.Thefootballmight/couldbeJack’s.Helikesallkindsofballgames.2.LiuMeiisn’theretoday.Shemight/couldbeill.can’t意为“不可能”,必用在否定句中。--Themancan’tbeMr.Green.--HehasgonetoAmerica.情态动词must,might,could,can’t表示推测的含义与用法。情态动词must,might,could,can’t后面都接动词原形，都可以表示对现在情况的揣测或推断，但他们的含义有所不同：must一定，肯定（100%的可能性）might,could有可能，也许（20%~80%的可能性）can’t不可能，不会（可能性几乎为零）活动探究意思推测程度must一定，肯定用于非常确定的推测maymight/could有可能，也许用于不确定的推测can/can’t不可能，不会在疑问句和否定句中表推测情态动词表示推测常考的有：对某事判断的程度：must＞could＞might＞can’tmust,could,might,can’tChoosemust,might,could,can’t,cantofillintheblanks.1.Thestorybook______behers.Ithashernameonit.2.Thebeautifultrousers______beLily’s.Becausethey’retoolong.3.Ican’tfindmykey.It____________beleftathome.4.Thevolleyball___________beSally’sorAnn’s.Theybothlikeplayingvolleyball.5.Thepiano____________belongtoAlice.Sheoftenplaysthepiano.mustcan’tcould/mightmight/couldmight/could7.Thepen___________belongtohim.It’sonhisdesk.might/could8.Mymother_________beathome.Shelefthomewithme.Shehasgonetogotowork.can’t9.Thisbasketball____________beNing’s.Heplaysbasketballeveryday.could/might10.Thisschooluniform_________beNick’s.It’stoosmallforhim.can’t6._____thatwalletyours?--No,it_______bemine.Mineishere.Cancan’t用must,could,can’t,might填空。1.--Excuseme,whosebookisthis?--It______beJohn’s.Ithashisnameonit.2.Theman________bemyEnglishteacher.HehasgonetoCanada.3.It__________beJim’sfootball.Helikesplayingfootballverymuch.mustcan’tmight/could【例1】--Jimisreadingabookunderthattree.--It_____beJim.HehasgonetoHainan.A.mayB.mustn’tC.can’tD.couldC典型例题解析【例2】--Whereareyougoingthismonth?--We_____gotoXiamen,butwe’renotsure.A.needn’tB.mustC.mightD.mustn’tC典型例题解析【例3】—Where'sMrLi?Ihavesomethingimportanttotellhim.—You____findhim.He______Japan.A.maynot,hasgonetoB.maynot,hasbeentoC.can’t，hasgonetoD.can't,hasbeentoC典型例题解析【例4】—CouldIlookatyourpictures?—Yes,ofcourseyou_________.A.couldB.canC.willD.mightB典型例题解析【例5】—WhereisJack，please?—He______beintheclassroom.［2013杭州］A.canB.needC.wouldD.mustD典型例题解析(可能是Mary。)(不可能是Mary。)Mum:Whoisit?J:ItmustbeTom.M:Itmight/couldbeMary.J:Itcan’tbeMary.SheisinChina.(一定是Tom。)(可能是Kate。)(绝对不是Marry。)Mum:Whoisit?Jim:(一定是