情态动词mustcan等表推测市公开课一等奖百校联赛获奖课件.pptx

第1页情态动词情态动词 can,could,may,might,must表推测表推测使用方法使用方法情情态动词态动词中中can,could,may,might,must都都表推表推测测。其中。其中mustcan/couldmay/might.must使用方法使用方法（1）表示推）表示推测测“可能性可能性”时时，意思是，意思是“一定、一定、准是准是”，语语气气较较必定，必定，较较有把握。有把握。He must be American.他准是个美国人。他准是个美国人。第2页（2）must表推测只能用于必定句表推测只能用于必定句。如表示如表示“一定不、必定不一定不、必定不”意思时，应意思时，应用用cant,如问询某种可能时，应用如问询某种可能时，应用can。He must know my address.他必定知道我地址。（一他必定知道我地址。（一定）定）He cant know my address.他必定不知道我地址。（一定不）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）他知道我地址吗？（问询可能性）第3页（3）must表示推表示推测时测时，能，能够够推推测现测现在在/正在正在发发生生动动作作/过过去去发发生生动动作作。He must have a car now.（现现在）他一定有在）他一定有辆辆小汽小汽车车。He must be doing his exercises in the classroom.（正在（正在进进行）他一定在教室里做行）他一定在教室里做练习练习。He must have finished the work.（过过去去发发生）他一定已完成了工作。生）他一定已完成了工作。注：注：must表示推表示推测时测时极少用于未来情况极少用于未来情况。普通不用。普通不用He must come tomorrow.可用可用Its certain/Im sure that he will come tomorrow.第4页（4）在反意疑）在反意疑问问句中，当从属部分含有表示推句中，当从属部分含有表示推测测意意义义must时时，疑，疑问问部分助部分助动词应动词应与与must后面后面动词动词在非推在非推测测情况下使用方法保持一致。情况下使用方法保持一致。He must be a worker,isnt he?（现现在）他按在）他按时时个工人，是个工人，是吗吗？You must have learned English for many years,havent you?（完成（完成时时）你一定学了好多年英）你一定学了好多年英语语，是，是吗吗？比比较较：It must have rained last night,didnt it?（过过去）昨晚一定下雨了，是不是？去）昨晚一定下雨了，是不是？He must have arrived by yesterday morning,hadnt he?第5页 can/could使用方法使用方法（1）can表示推表示推测测“可能性可能性”时时，往往用于否定，往往用于否定句或疑句或疑问问句。句。Cant“一定不一定不”，can在疑在疑问问句中句中意思是意思是“会、可能会、可能”。He cant be at home.=It is impossible that he is at home.他一定不在家。他一定不在家。（2）can/cant+have done，表示，表示对过对过去去发发生生动动作作进进行推行推测测。He cant have gone to Shanghai for I saw him a minute ago.他不可能去了上海，我他不可能去了上海，我刚刚才才还还看看见见他。他。Its so late.Where can she have gone?天晚了，天晚了，她可能去哪儿了呢？她可能去哪儿了呢？第6页（3）could 还还能能够够用于表示客气、委婉、用于表示客气、委婉、礼貌礼貌请请求求语语气。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，表虚本能做但未做，表虚拟语拟语气气 I could have done it well，but I wasnt so careful then.第7页may和和might使用方法使用方法（1）may,might表示推表示推测测“可能性可能性”时时，意思，意思是是“可能可能”、“可能可能”He may/might be American.=It is possible that he is American.他可能是个美国人。他可能是个美国人。注：注：might不表示不表示过过去去时态时态，只是，只是语语气上比气上比may更委婉，表示可能性更小。更委婉，表示可能性更小。（2）may,might表推表推测时测时，能，能够够用于否定句，用于否定句，意思是意思是“可能不、可能不可能不、可能不”，但，但不用于疑不用于疑问问句句。He may/might not be at home.他可能不在家。他可能不在家。第8页（3）may,might能能够够推推测现测现在正在在正在发发生生动动作或作或过过去去发发生生动动作。作。He may/might be sleeping now.The boy may/might not be watching TV at home.这这个男孩可能没在家看个男孩可能没在家看电视电视These students may/might have seen the film before.（过过去）去）这这些学生以前可能看些学生以前可能看过这过这部部电电影。影。第9页u 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第10页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 to3.Peter _come with us tonight,but he isnt very sure.A.must B.may C.can D.will第11页 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;can5.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第12页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 see7.David,you _play with the valuable bottle,you_ break it.A.wont;cant B.mustnt;mayC.shouldnt;must D.cant;shouldnt第13页8.Susan refuses to marry Jack now.She _her mind.A.must change B.should have changedC.must have changed D.would have changed第14页9.Sue_ come together with us tonight,but she isnt very sure yet.A.must B.may C.need D.will第15页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第16页could have done过去原来能够过去原来能够”实际上没能做实际上没能做I could have run 100 metres in 12 seconds.我原来能用我原来能用12秒钟完秒钟完100米米.（实际上没能）（实际上没能）If you could have finished the task in time，you could have been promoted.假假如如你你当当初初能能准准期期完完成成那那任任务务话话，你你可可能能已已提提升升了（实际上没有被提升）了（实际上没有被提升）第17页情态动词情态动词+have+done”表表“原来应该原来应该”should have done过去本应该做而没做过去本应该做而没做should not have done本不本不应该应该 而而实际实际上却已上却已经经”We should have studied last night,but we went to the concert instead。You shouldnt have climbed that hill，it is too dangerous.第18页need not have done它表示过去已做事，实际上没有必要。它表示过去已做事，实际上没有必要。(不不需要做而做了）需要做而做了）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）我原来无须要那么早起床（实际上早已起床）I need not have waited for the train for an hour.我我原原来来无无须须要要等等一一个个小小时时火火车车。（实实际际上上已已经经等等了一个小时）了一个小时）第19页Practice1.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第20页1.I can run fast.(否定句)2.You must return the book now.（普通疑问句而且否定回答）3.He can play basketball well.（普通疑问句）4.They must take the books out of the room.（否定句）5.Need he go to school tomorrow.(必定否定回答）6.Daniel must watch TV every evening.(改为否定句)7.I cant do my homework every day.(改为必定句)8.Youll need your book and pen.(改为否定句)第21页