资源描述
上一页,首 页,下一页,本资料仅供参考,不能作为科学依据。谢谢。本资料仅供参考,不能作为科学依据。本资料仅供参考,不能作为科学依据。谢谢。本资料仅供参考,不能作为科学依据。,ModalVerbs,1/23,情态动词 can,could,may,might,must表推测使用方法:,情态动词中,can,could,may,might,must,都表推测。其中,must,可能性最大,,can/could,次之,,may/might,最小。详细使用方法以下:,1.must,使用方法,(,1,)表示推测“可能性”时,意思是“一定、准是”,语气较必定,较有把握。,He must be American.=It is certain that he is American.,他准是个美国人。,2/23,(,2,),must,表推测只能用于必定句。,如表示“一定不、必定不”意思时,应用,cant,如问询某种可能时,应用,can,。,He must know my address.,他必定知道我地址。,(一定),He cant know my address.,他必定不知道我地址。,(一定不),Can he know my address?,他知道我地址吗?,(问询可能性),3/23,(3,),must,表示推测时,能够推测现在,/,正在发生动作,/,过去发生动作。,He must have a car now.,(现在)他一定有辆小汽车。,He must be doing his exercises in the classroom.,(正在进行)他一定在教室里做练习。,He,must have finished,the work.,(过去发生)他一定已完成了工作。,注:,must,表示推测时,极少用于未来情况,。普通不用,He must come tomorrow.,可用,Its certain/Im sure that he will come tomorrow.,4/23,(,4,)在反意疑问句中,当从属部分含有表示推测意义,must,时,疑问部分助动词应与,must,后面动词在非推测情况下使用方法保持一致。,He must,be,a worker,isnt,he?,(现在)他按时个工人,是吗?,You must,have learned,English for many years,havent,you?,(完成时)你一定学了好多年英语,是吗?,比较:,It must,have rained,last night,didnt,it?,(过去)昨晚一定下雨了,是不是?,He,must,have arrived,by yesterday morning,hadnt he?,5/23,2.can/could,使用方法,(,1,),can,表示推测“可能性”时,往往用于否定句或疑问句。,Cant,“一定不”,,can,在疑问句中意思是“会、可能”。,He cant be at home.=It is impossible that he is at home.,他一定不在家。,(,2,),can/cant+have done,,表示对过去发生动作进行推测。,He,cant have gone,to Shanghai for I saw him a minute ago.,他不可能去了上海,我刚才还看见他。,Its so late.Where,can,she,have gone,?,天晚了,她可能去哪儿了呢?,6/23,(3,),could 还能够用于表示客气、委婉、礼貌请求语气。,Excuse me,could you tell me the way to the bus station?Could you help me?,(4)could have done,本能做但未做,表虚拟语气,I could have done it well,but I wasnt so careful then.,7/23,3.may,和,might,使用方法,(,1,),may,might,表示推测“可能性”时,意思是“可能”、“可能”,He may/might be American.=It is possible that he is American.,他可能是个美国人。,注:,might,不表示过去时态,只是语气上比,may,更委婉,表示可能性更小。,(,2,),may,might,表推测时,能够用于否定句,意思是“可能不、可能不”,但,不用于疑问句,。,He may/might not be at home.,他可能不在家。,8/23,(,3,),may,might,能够推测现在正在发生动作或过去发生动作。,He,may/might be sleeping,now.,The boy may/might not be watching TV at home.,这个男孩可能没在家看电视,These students,may/might have seen,the film,before.,(过去),这些学生以前可能看过这部电影。,9/23,Choose the best answers:,1.I thought you_ like something to read.So I have brought you some books.A.ought B.might,C.would D.must,10/23,2.That man must be Sarahs husband.-No,he_ be her husband.She is still single.A.cant B.mustnt,C.may not D.ought to,3.Peter _come with us tonight,but he isnt very sure.A.must B.may C.can D.will,11/23,4.What_ it be?-It_ be a mail box,for it is moving.,It_ be a car.,A.can;cant;must B.can;can;mustC.can;mustnt;must D.must;mustnt;can,5.Look,someone is coming.Guess_.-Jack.Hes always on time.A.who can it be B.who he mayC.who he can be D.who it can be,12/23,6.I saw Mary in the library yesterday.-You_ her.She is still abroad.A.mustnt see B.cant have seen C.mustnt have seen D.couldnt see,7.David,you _play with the valuable bottle,you_ break it.A.wont;cant B.mustnt;mayC.shouldnt;must D.cant;shouldnt,13/23,8.Susan refuses to marry Jack now.She _her mind.A.must change,B.should have changedC.must have changed,D.would have changed,14/23,9.Sue_ come together with us tonight,but she isnt very sure yet.A.must B.may,C.need D.will,15/23,10.Aunt Margaret_ the train,otherwise she would have arrived here by now.A.must have missed,B.should have missedC.had missed,D.might miss,16/23,情态动词+have+done”,表“原来应该”,使用情况分析,一、should have done过去原来应该,(而实际上并没有),should not have done 本不应该 而实际上却已经”,如:1、We should have studied last night,but we went to the concert instead.我们昨晚本应学习,但我们却去看音乐会了。(实际上没有学习),17/23,二、could have done,它表示“过去原来能够”实际上没能做。,如1、I could have run 100 metres in 12 seconds.,我原来能用12秒钟完100米.(实际上没能),2、If you could have finished the task in time,you could have been promoted.,假如你当初能准期完成那任务话,你可能已提升了(实际上没有被提升),18/23,三、need not have done,它表示过去已做事,实际上没有必要。,如,1、I need not have got up so early.,我原来无须要那么早起床(,实际上早已起床,),2、I need not have waited for the train for an hour.我原来无须要等一个小时火车。,(实际上已经等了一个小时),问题:,would have done,在什么情况下使用呢?,19/23,四、would have done 用在虚拟语气中,表示与过去事实相反之假设结果,常与if 条件句连用,。,1、I,would have helped,you,if,I,had known,of your difficulties.要是我当初知道你们窘境,我就会帮助你了(而实际上没有帮助你),2、If it hadnt rained yesterday,we would have gone out for a walk.假如昨天没下雨,我们就去散步了。,(实际上没有去)。,20/23,Practice,1.Mr White _ at 8:30 for the meeting,but he didnt turn up.,A.should have arrived,B.should arrive,C.should have had arrived,D.should be arriving,21/23,2.If he had been here yesterday,he _ this pop star.,A.would meet,B.would have met,C.met,D.must have met,22/23,3.It is hard for me to imagine what I,would,be doing today,if,I_ in love at the age of seven with the Melinda Cox Library in my hometown.,A.wouldnt have fallen,B.had not fallen,C.should fall,D.were to fall,23/23,
展开阅读全文