1、can/could:1.can 一般表示与生俱来的能力或一般表示与生俱来的能力或者一种客观可能性者一种客观可能性,还可以表示请还可以表示请求和允许求和允许。Learning English _ be difficult.canMan can not live without air._ I use your bike?Cancan/could:2.在疑问句中，用在疑问句中，用could可表示请可表示请求，语气较委婉。求，语气较委婉。_I have the television on?Yes,you _./No,you _CouldHe asks if he _ smoke here.could
2、can/maycant/Im afraid notcan/could:3.表示惊异、怀疑、不相信的态度。（主表示惊异、怀疑、不相信的态度。（主要用在否定句、疑问句或惊叹句中）要用在否定句、疑问句或惊叹句中）Hes such a nice person that he _ commit the crime.cant你怎么会如此地粗心！你怎么会如此地粗心！How can you be so careless!Can this be true?can/could:4.can never/canttoo表示表示“无无论怎样论怎样也不过分也不过分”，“越越越好越好”。你过马路的时候再小心也不为过。你过马
3、路的时候再小心也不为过。You cant be too careful while crossing the road.can/be able to区别区别:Edison always wondered why hens could hatch(孵孵)chickens while he was not able to.Question:Are the two modal verbs interchangeable(互换互换)?If not,why?can表示表示或或，而，而be able to更加强调更加强调或者或者，能做到的事情。能做到的事情。can/be able to区别区别:1.A b
4、ig fire broke out in ABC hotel yesterday.Luckily,everyone _ run out of the building.was able to2.She _ speak both English and French.canadvisabilitynecessityought to/shouldhave tomustYour mother brings you up and takes good care of you,so when she is old,you _ look after her in return.A.can B.may C.
5、have to D.must very uncertainalmost certainmightshouldmustmaycouldought towill1.He _ be at home.2.He _ be at home,for he just called me from his home 15 seconds ago.A.may B.might C.must A.may B.might C.must (can)1.must 表示肯定的猜测，译为表示肯定的猜测，译为“一定一定”，不，不能用于否定句或疑问句。能用于否定句或疑问句。2.This must be your pen.3.He
6、must be doing his homework now.4.He must have arrived already.mustmust2.表示表示“坚持坚持”（常用于固定句型：（常用于固定句型：if you must do sth.如果你非得要做某事）如果你非得要做某事）如果你真的要走，那就悄悄离开。如果你真的要走，那就悄悄离开。If you must leave,do it quietly.They_ be doing the experiment in the lab.Why？Because the lights are still burning.A.could B.can C.m
7、ust D.would may/might:1.表示许可。表示请求、允许时，表示许可。表示请求、允许时，might比比may的语气更委婉一些。的语气更委婉一些。Might/May I use your computer?Yes,you can./No,you cant/mustnt.may/might:2.用于祈使句中表示祝愿。用于祈使句中表示祝愿。3.表示推测、可能（只用于肯定句，表示推测、可能（只用于肯定句，疑问句则要用疑问句则要用can或或could）。）。祝你成功！祝你成功！May you succeed.He may be very busy now.May you be happy
8、 all your life.5.Making requests(提出要求提出要求):Can you help me with my training?I dont know how to use this equipment!will can could wouldinformalformal6.Making suggestions(提出建提出建议议):Shall we do the training in the morning?Its too hot to take exercise in the afternoon.shall:1.Shall用于第一、第三人称疑问用于第一、第三人称疑问
9、句中，表示说话人征求对方的意句中，表示说话人征求对方的意见、向对方请示或提供帮助见、向对方请示或提供帮助。1.Shall we begin our lesson?2.When shall he be allowed to leave hospital?3.Shall I carry this bag for you?shall:2.Shall用于第二、第三人称，表用于第二、第三人称，表示说话人给对方命令、警告、允示说话人给对方命令、警告、允诺或威胁。诺或威胁。You shall fail if you dont work harder.He shall be punished accordin
10、g to the rule.等我读完这本书，就会给他的。等我读完这本书，就会给他的。He shall have the book when I finish it.警告警告威胁威胁允诺允诺7.Making offers(提供帮助提供帮助):Dont worry,dear,I will wash them right away.Mom,my dirty clothes have been piled up!I dont have timewill/would:1.表示请求、建议等，表示请求、建议等，would比比will委婉客气。委婉客气。sentence pattern Would you p
11、leaseWould you mindWould ratherWould you likewill/would:2.表示意志、愿望和决心。表示意志、愿望和决心。I will never do that again.will/would:3.可表示经常性、习惯性、倾向可表示经常性、习惯性、倾向性。翻译为性。翻译为“经常、惯于、总是经常、惯于、总是”。1).The old man _have a smoke under a big tree every afternoon after he finished his farm work.would2).门就是打不开门就是打不开!The door w
12、ont open.will/would:I will go to the park with you tomorrow if you will offer me lunch.Question:Is this sentence correct?Why?情态动词情态动词表示表示“意愿意愿”should:1.Should表示劝告、建议、命令，表示劝告、建议、命令，其同义词是其同义词是ought to；在疑问句中，；在疑问句中，通常用通常用should代替代替oughtto。Should I open the window?我们应当要相互学习。我们应当要相互学习。We should learn fro
13、m each other.should:2.情态动词情态动词should用于第一人称用于第一人称时可以表示说话人的一种谦逊、时可以表示说话人的一种谦逊、客气、委婉的语气。客气、委婉的语气。RoseSure.By the way,who is your idol?JackLiu Xiang,I should say.I should advise you not to do that again.3.should表示意外或惊讶表示意外或惊讶 常译为常译为 “居然，竟然居然，竟然”。I cant believe such a gentleman should be so rude to the o
14、ld.我不敢相信这样一个绅士居然对老人我不敢相信这样一个绅士居然对老人如此无礼。如此无礼。should:4.should 表示猜测时，一般指按经验或逻辑表示猜测时，一般指按经验或逻辑判断，翻译成判断，翻译成“照说应该，估计，想必照说应该，估计，想必”should:-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.need三三.“情态动词情态动词+have done”的用法的用法（1）must have done对过去某事
15、的十分肯定猜测对过去某事的十分肯定猜测（2）may/might have done对过去某事的可能性对过去某事的可能性猜测猜测（3）cant/couldnt have done对过去某事的否定对过去某事的否定猜测猜测（4）should/ought to have done过去应该做而未过去应该做而未做做（5）shouldnt/oughtnt to have done 过去不应该做而实际上做了过去不应该做而实际上做了（6）neednt have done 本没有必要做的事实际本没有必要做的事实际却做了却做了（7）could have done 本来能够做的（有能力做）事实际却未做到本来能够做的（
16、有能力做）事实际却未做到Practice1.With so much work on hand,you _to see the game last night.2.A.mustnt go B.could have goneC.shouldnt go D.shouldnt have gone2.There was plenty of time.She _.A.mustnt have hurried B.couldnt have hurriedC.must not hurry D.neednt have hurriedPractice3.I saw Mary in the library yest
17、erday.-You_ her.She is still abroad.A.mustnt see B.cant have seen C.mustnt have seen D.couldnt see4.Aunt Mary_the train,otherwise she would have arrived here by now.A.must have missed B.should have missedC.had missed D.might miss四四.可兼做行为动词的情态动词：可兼做行为动词的情态动词：need、dare 情态动词(+动词原形)行为动词needdare 1.1.无人称和
18、数的变化无人称和数的变化;2.2.尤其用于：尤其用于：*否定句及疑问句中否定句及疑问句中;*在在if/whetherif/whether之后之后;*或与或与hardlyhardly,nevernever,no oneno one,nobodynobody连用连用;3.3.常以常以needntneednt 和和darentdarent 的形式出现的形式出现;4.dare4.dare有其过去时有其过去时dareddared.多用于肯定句多用于肯定句;(sb.)need to do dare to do(sth.)need to be done(sth.)need doing He darent s
19、peak English before such a crowd,dare he?判断正误判断正误:He darent to speak English before such a crowd,did he?These dishes need be cleaned carefully.These dishes need to be cleaned carefully.These dishes need cleaning carefully.五五.表示否定的情态动词的用法表示否定的情态动词的用法:部分情态动词的否定式是情态动词中的考点部分情态动词的否定式是情态动词中的考点之一。之一。mustnt 不准不准,禁止禁止 neednt 没必要没必要(=dont have to)cant 不能不能;不可能不可能may not 不可以不可以;可能不可能不shouldnt 不应该不应该(=ought not to)
