情态动词用法总结.ppt

情态动词用法,情态动词的语法特征,2)情态动词不能单独做谓语,后面只能接动词原形，ought to和have to除外，。,3)情态动词没有人称,数的变化,但有些情态动词,如can、will、shall、have to、may等有过去式。,1）情态动词表说话人的某种感情或语气，对某一动作或状态的某种态度。,1)Some of us can use the computer now,but we couldnt last year.2)Can/Could I use your dictionary?3)Could you lend me a hand?4）Can she be in the computer center?5)I though what he said could not be true.,1.表能力,意为“能，能够”，can指现在，could指过去。,2.表示“请求”“允许”(表请求时，口语中常用 could 代替 can 使语气更委婉，回答时用can),3.表示推测，意为“可能”“或许”，用于疑问句或否定句，cant和couldnt意为“不可能”。,1.can 与could,You can hurt yourself if you play in the street.,Shanghai can be very cold in March.,5.can 用于疑问句或否定句中时，表惊异、不相信等，意思是“可能、能够”。,How can you believe such a liar like him?,Can this be true?,Hes such a nice person that he _ commit the crime!,cant,How can you be so careless!,4.can用于肯定句中表示理论上的可能性，并不牵涉是否真的会发生,can表示“能够”时与短语be able to同义，但can只用于一般现在时或过去时，而后者可用于各种时态。另外，can表示个人有某种能力，而be able to表示某人通过努力、克服困难做成某事，相当于succeed in doing sth.；,can/be able to,Attention:,can/be able to区别:,A big fire broke out in ABC hotel yesterday.Luckily,everyone _ run out of the building.,was able to,2.She _ speak both English and French.,can,7,1.Can,Could 过去式；语气更委婉,Can 表示习惯能力 而be able to表示一次努力做成了某事。2时态,1.在否定、疑问句中表示“对过去发生行为 的可能性猜测。2.在肯定句中表示“本来可以做而未做”,could 是can的过去式,表示过去 的能力,许可和推测,(4)can的其他用法。“cant+be/行为动词+比较级”表示“再没有比更”。*I cant think of a better idea.这个主意真是太好了。“cant+动词原形+too/enough”表示“无论怎么也不过分”。*I cant praise this film highly enough.我无论怎样赞扬这部电影也不过分。“cant+help+动名词”表示“禁不住做某事”。*When hearing that,every one of us could not help laughing.我们大家听到那件事,都忍不住笑了。“cant+(choose/help)but+动词原形”表示“不得不,只好”。,2.may 与might,1.表示“许可”或“请求”，有“可以”的意思，口语中常用 might 代 may,表示委婉语气。否定回答时用“must not”表“禁止，阻止”，不用“may not”.“may not”表示“可能不”。,Eg:1)-May I watch TV after supper?-Yes,you may./No,you mustnt.2)Today is Sunday.She may not in her office now.,2.表示推测。意为“或许，可能”might 比 may 可能性小。,Eg:1)The girl might be sleeping this time of day.2)He may come,or he may not.,5.may/might as well+动词原形“不妨干某事,还不如”,Eg:You may as well go and have a look.,4.may/might have done 表示对过去发生过的事情的推测，意为“可能已经做过某事”,Eg:I cant find my sunglasses.I may/might have left them in your office.,May you have a good journey!祝你旅行愉快！May you succeed!祝你成功！,3.may用于祈使句表示祝愿。,11,1.May,Might 过去式；语气更委婉,2.may/might+have+p.p,在否定、肯定句中表示对过去动作的推测“也许是”,Eg.1.She may be still waiting for us.2.May I come in?3.May you have a happy holiday.,Eg.He might have spoken to her yesterday.,Yes,you may/can.,No,you cant/mustnt,Shi Dongpeng might win a medal at the Olympic Games.,Although the chance of winning a medal is small,Ill try my best!,3.will 与would,1.用于第二人称的疑问句中，表“请求、建议”等，用 would 比用will 委婉，客气些,Eg:1)Will you lend me your book?2)Would you like a cup of tea?,2.用于表示意志或意愿，意为“会，愿意”。will 指现在，而 would 指 过去。用于否定句中，表示“不会、不肯、不乐意”。,Eg:1)I wont do that again.2)They said that they would help us.,3.表示习惯、特征。译作“总是、惯于”，will 指现在常常，would 指过去常常。,1)Mary will keep asking some silly questions.2)Oil will float on water.,would与used to 两者均表示“过去常常”，但would仅表示过去的习惯性动作(不表状态)，现在有可能还如此，也可能不再那样；used to既表示过去的动作也表示过去的状态，不过现在不再做或不再有那种状态了。Eg：That will be the book you want.,4.表推测，意为“可能、大概”,15,Will/would,1、Would 后只能接表示动作的动词。,2、used to 则还可以接表示状态的动词。Eg.He used to be a worker.,4.shall,1.Shall用于第一、三人称的疑问句中，表示说话人征求对方的意见或请求。,Eg:1)Shall we begin our discussion?2)Shall Tom go there with me tomorrow?3)Henry is waiting outside.Shall he come in?,2.Shall用于二、三人称的陈述句，表示说话人 的允诺、警告、命令、威胁等语气。,Eg:1)You shall get an answer from me tomorrow.2)He shall be punished.3)You shall go with me.4)Persons under 18shall not be employed in night work,Shall we do the training in the morning?,Its too hot to take exercise in the afternoon.,should,1.Should表责任、义务，意为“应该”,3.表惊讶。意为“竟然，居然”,Eg:1)Its 7 oclock,he should be at home.2)There shouldnt be any difficulty passing the road test since you have practiced a lot in the driving school.,2.Should表推测，意为“按道理应该”,Eg:We should learn from each other.,Eg:1)Its surprising that Mary should love such a person.2)Its unbelievable that the boy should sing such a beautiful song.,4.ought to/should have done 本应该干某事可事实未干 oughtnt to/shouldnt have done本不该干某事可事实 却干了,Eg:You should have invited me to the party.You shouldnt have eaten all the cakes in one day.,20,1、Shall,3、shall/should+have+p.p ought to,表示本应该做而未做。,Eg.You should have finished it five minutes ago.,2.should,MustIfinishallhomeworkatatime?,Yes,you must.No,youneednt/dont have to.,1.must表义务强制。用于一般问句中,肯定回答用must,否定回答用neednt或dont have to，意为“不必”。mustnt表示“禁止，不允许”,5.must/haveto/need,The law states that people mustnt drive after drinking alcohol.,I dont like this TV set.We must buy a new one.Mother was out,so I had to look after the shop.,表示“必须”这个意思时，must和haveto稍有区别。must着重说明主观看法，haveto强调客观需要。另外，haveto能用于更多时态。,注意对need问句的回答:-Need I finish the work today?-Yes,_.No,_.No,_.,you must,you neednt,you dont have to,-Must we do it now?-No,you _.,neednt(dont have to),Youmustbethenewteacher.Hemustbejoking.Thereisnobodyhere.Theymusthaveall gonehome.,2.must 表示猜测,作“准是”,“一定”,一般用于肯定句中。must have done对过去发生的事情作肯定判断用,3.must 表示“偏要，偏偏”,Why must you always interrupt me?If you must smoke,do it outside,pleaseWhy must it rain on Sunday?,25,1.Must,表示“必须”，而mustnt 表示“禁止、不准”表示肯定的猜测,但只用于肯定句，3.表示感情色彩，意为“偏偏；偏要”，,Must表示主观Have to表示客观需求,3.must+have+p.p,对过去事情的肯定猜测。,Eg.The road is wet.It must have rained last night.,情态动词+have done这是历年高考热点之一，可表示“推测、责备、怀疑”等多种意义。,一、表示对过去事情的推测或估计,1.must have done“过去肯定已经做了某事”eg:The ground is rather wet,so it must have rained last night.2.may/might have done“可能/大概已经做了某事”eg:Tom may have gone to shanghai,but I still not sure about it.3.cant/couldnt have done“不可能已经做了某事”eg:The ground is very dry,so it cant have rained last night注：在疑问句中 can/could 表示对过去情况的疑问性 推测，“可能已经了吗？”eg:Someone must have broken into our bedroom,Who could have done it?,二、表示对过去所发生事情的遗憾或责备,1.should/ought to have done“过去本应该做而没做”eg:I really regretted wasting the hours when I should have studied hard,but it was too late.2.shouldnt/oughtnt to have done“过去本不应该做的事却做了”eg:Im very sorry for the words I shouldnt have said to you at that moment.3.could/might have done“本来能够做的事却没做”eg:He could have worked out the problem.,4.neednt have done“原本不必做的事却做了”eg:Your home is not far from your school,so you neednt have left in such a hurry.,5.Would like to have done“本打算做某事但没做成”eg:I would like to have come to visit you,but I had to look after my sick mother at home.,情态动词表推测用法小结,Michael _ be a policeman,for hes much too short.A.neednt B.cant C.should D.may2.Mr.Bush is on time for everything.How _ it be that he was late for the opening ceremony?A.can B.should C.may D.must3.-I stayed at a hotel while in New York.-Oh,did you?You _ with Barbara.A.could have stayed B.could stay C.would stay D.must have stayedMy sister met him at the Grand Theater yesterday afternoon,so he _ your lecture.A.couldnt have attended B.neednt have attended C.mustnt have attended D.shouldnt have attended,B,A,A,A,5.Theres someone outside.Who _it be?A.can B.need C.may D.must6.-Is Jack on duty today?-It _ be him.Its his turn tomorrow.A.mustnt B.wont C.cant D.neednt7.It is usually warm in my hometown,but it _be rather cold sometimes.A.can B.need C.dare D.must8.The fire spread through the hotel very quickly,but everyone _ get away.A.were able to B.would C.was able to D.could,A,C,A,C,1.Sorry Im late.I _ have turned off the alarm clock and gone back to sleep again.A.might B.shouldC.can D.will2.Peter _ come with us tonight,but he isnt very sure yet.A.must B.may C.can D.will,A,B,Chairman Zhang,many people want to see you._they wait here or outside?A.shall B.can C.should D.may2.You _use my bike if you can return it to me before Ileave here.A.should B.shall C.need D.must3.You _be punished if you break the rule.A.shall B.should C.need D.must,A,B,A,1.You cant imagine that a well-behaved gentleman _ be so rude to a lady.A.can B.should C.may D.must2.-When can I come for the photos?I need them tomorrow afternoon.-They _ be ready by 12:00 A.can B.should C.might D.need3.We _ last night,but we went to the concert instead.A.must have studied B.might study C.ought to have studied D.would study,B,B,c,【考例】-Jane has just come back from China and she looks happy.-She _ her trip very much.must enjoy B.must have enjoyedC.may enjoy D should have enjoyed,【考例】Where is Dad,Mary?He _ the flowers in the garden.must water B.must be wateringC.Must have watered D.watered,【考例】-Whats the matter with the man hanging his head there?-Well.If you _know,he was caught stealing my bike.must B.may C.can D.shall,