1、GrammarModal verbs 情态动词情态动词 Contents 情态动词的定义&特征 情态动词的基本用法 情态动词的特殊用法 情态动词+have done动词的种类动词的种类 特点和例句特点和例句行为动词行为动词 或实义动词或实义动词 连系动词连系动词助动词助动词情态动词情态动词1.及物动词：后必须跟宾语 Eg.They study English.She eats an apple every day.2.不及物动词：后需加介词才能跟宾语The flag rises.They listen to English every morning.连系动词后跟表语。助动词无特殊意义，帮助构
2、成否定句、疑问句、正在进行时态、完成时态或被动语态等,常见助动词有be,do,haveWe dont like the film.我们不喜欢这部电影。（用于否定句）Tom is doing his homework.汤姆正在做作业。（用于正在进行时态）He has finished his work.他已经完成了工作。（用于完成时态）情态动词后须跟动词原形。情态动词有will,can,may,must,need等You may go now.你可以走了。I will be there on time.我会准时到那儿的。Eg.She is beautiful./She is a student.
3、His face turn red.Your coat looks nice.be动词、助动词和情态动词变否定形式在其后直接加not.行为动词和除be动词以外的系动词，变否定形式要在其前加dont 或doesnt。可单独使用必须与行为动词或系动词连用构成谓语情态动词的语法特征情态动词的语法特征1）情态动词情态动词不能单独做谓语不能单独做谓语，它与其他动词构成谓语时，总是，它与其他动词构成谓语时，总是放在其他动词之前放在其他动词之前。3）情态动词没有情态动词没有人称，数人称，数的变化，但有些情态动词，如的变化，但有些情态动词，如can、will也有一般式和过去式也有一般式和过去式的变化。的变化。
4、4）情态动词的情态动词的“时态时态”形式并不是时间区别的主要标志，不少情况下，情态动词形式并不是时间区别的主要标志，不少情况下，情态动词的现在式形式和过去式形式都可用来表示现在时间、过去时间和将来时间。的现在式形式和过去式形式都可用来表示现在时间、过去时间和将来时间。2）除）除ought和和have外，后面只能接外，后面只能接不带不带to的不定式。的不定式。can/could may/might will/would shall/should must ought to need have to 情态动词+have done1)Some of us can use the computer n
5、ow,but we couldnt last year.2)The new-built theatre can seat 1500 people.3)Can she be in the computer center?4)I though what he said could not be true.can在肯定句中表可能性时，表示理论上的可能性。在肯定句中表可能性时，表示理论上的可能性。Even expert can make mistakes.He can be very friendly at times.“有时候会有时候会”5)Can/Could I use your dictiona
6、ry?6)Could you lend me a hand?1.1.表能力表能力3.表示表示“请求请求”“允许允许”(表请求时，口语中常用表请求时，口语中常用 could 代替代替 can 使语气更委婉，回答时用使语气更委婉，回答时用can)2.表示推测，意为表示推测，意为“可能可能”“”“或许或许”，用于疑问句或否定句，用于疑问句或否定句1.can 与与could4.表示表示“许可许可”，可与，可与may 换用。换用。You can go home now.5.can 用于疑问句或否定句中时，表惊异、不相信等，用于疑问句或否定句中时，表惊异、不相信等，意思是意思是“可能、能够可能、能够”。C
7、an this news be true?How can you be so foolish?6.cant/couldnt+have+done 表示对过去情况的否定推测表示对过去情况的否定推测Susan cant have written a report like this.7.could+have+done 表示对过去能做而未做的事情表示对过去能做而未做的事情 感到惋惜，遗憾感到惋惜，遗憾Its a pity.Your class could have got the first prize.can,could和和beableto的用法的用法She can/be able to sing
8、the song in English.This machine can make you feel comfortable.1.can,beableto都可都可表示表示“能力能力”can的主语是的主语是人或物人或物,beableto的主语是的主语是人人Well be able to finish the work soon.I havent been able to see the film.2.can只用于现在式和过去式只用于现在式和过去式(could)。beableto可以用于各种时态。可以用于各种时态。could用于表示泛指过去的能力。如：用于表示泛指过去的能力。如：Icouldrea
9、dwhenIwasfour.Although the soldier was badly wounded,he was able to tell what had happened.She ran fast but she couldnt/wasnt able to catch the bus.3.表示特定的某一过去能力或表示成功地做了某事时，只能用表示特定的某一过去能力或表示成功地做了某事时，只能用was/wereableto，不能用不能用could。He was able to flee Europe before the war broke out.He was able to swim
10、 halfway before he got tired.表示过去的能力表示过去的能力注意注意can的惯用语的惯用语1.cannot(help/choose)but do2.can but do3.cannot help doing4.cant help sb.doing sth.5.cant help sb.do sth.6.cant help(it)7.cannot too 不得不，只能不得不，只能只好，不得不只好，不得不忍不住忍不住不能让某人不做某事不能让某人不做某事不能帮忙做某事不能帮忙做某事控制不住，没有办法控制不住，没有办法越越越好越好2.may 与与might1.表示表示“许可许
11、可”或或“请求请求”，有，有“可以可以”的意思，口语中的意思，口语中 常用常用 might 代代 may,表示委婉语气。表示委婉语气。否定回答时用否定回答时用“must not”表表“禁止，阻止禁止，阻止”，不用不用“may not”.“may not”表示表示“可能不可能不”。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.can也可表示许可或请求，但语气较强烈。也可表示许可或请求，但语气较强烈。2.表示可能性。表示可能性
12、。意为意为“或许，可能或许，可能”might 比比 may 可能性小。可能性小。Eg:1)It might be true.2)They may be in the library now.3.may/might as well+动词原形动词原形“还是还是的好的好”Eg:You may as well go and have a look.4.May you+动词原形动词原形 表表“希望、祝愿、祈求希望、祝愿、祈求”“祝你祝你”Eg:May you succeed.3.will 与与would 1.表表“请求、建议请求、建议”等。常用等。常用在疑问句中在疑问句中,第二人称。第二人称。用用 wo
13、uld 比用比用will 委婉，客气些委婉，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。用于表示意志或意愿。will 指现在，而指现在，而would 指过去。指过去。Eg:1)Ill never do that again.2)They said that they would help us.用于否定句中，表示用于否定句中，表示“不肯、不乐意不肯、不乐意”Eg:No matter what I said,he wont listen to me.3.表示习惯性动作。表示习惯性动作。译
14、作译作“总是、惯于总是、惯于”will 指现在，指现在，would 指过去。指过去。Eg:1)Fish will die without water.2)Every evening,she would sit by window,deep in thought.4.表示功能，译作表示功能，译作“能、行能、行”Eg:1)That will be all right.2)This door wont open.4.should1.用于表劝告、建议。用于表劝告、建议。意为意为”应该、应当应该、应当”。=ought toEg:You should keep your promise.2.用于表达合理的
15、推断（用于表达合理的推断（意为意为“应该应该”），或明显的结果（意为），或明显的结果（意为“可能可能”）。所）。所涉及的事情几乎是事实。涉及的事情几乎是事实。Eg:1)Its 7 oclock,he should be at home.2)They should have arrived by now.3.表示惊讶，忧虑，惋惜等情绪，意为表示惊讶，忧虑，惋惜等情绪，意为“竟会，竟然竟会，竟然”Eg:I find it quite astonishing that he should be so rude to you.5.shall 与与will1.shall 与第与第一、三一、三人称连用，且
16、用在人称连用，且用在疑问句疑问句中时，中时，表说话人表说话人征求听话者的允诺征求听话者的允诺。will 与第与第二二人称连用，且出现在人称连用，且出现在疑问句疑问句中时，中时，表示请求。表示请求。would 更客气。更客气。Eg:1)Shall we begin our discussion?2)Shall the driver wait?3)Will you speak louder,please?2.shall的主语是第的主语是第二、三二、三人称的人称的陈述句陈述句，表示说话人，表示说话人 的允诺、警告、命令等语气。的允诺、警告、命令等语气。Eg:1)You shall get the b
17、ook tomorrow.2)He shall be punished.3)You shall go with me.4)If you come to my house,I will show you my new painting.用在法律，条约，规章，预言等文件中，无论主语人称如何，一律用用在法律，条约，规章，预言等文件中，无论主语人称如何，一律用shall,表示义表示义务，规定。务，规定。允诺允诺警告警告命令命令6.must1.表示义务或强烈的劝告，意为表示义务或强烈的劝告，意为“必须必须”“”“应该应该”，其否定式表示其否定式表示“不应该不应该”“”“不许可不许可”“不准不准”“”“禁
18、止禁止”。Eg:1)You must finish your homework first.2)Children mustnt speak like that to their parents.2.回答回答 must 所在的一般疑问句时，否定回答用所在的一般疑问句时，否定回答用 “neednt”“dont have to”.Eg:-Must we finish the work tomorrow?-No,you neednt/dont have to./Yes,you must.3.表推测，用于肯定句，意为表推测，用于肯定句，意为“一定一定”“”“必然会必然会”。Eg:1)Betty must
19、 be in the next room.2)He must be watering the flowers in his garden.Must you go swimming in such a cold day?4.must表示表示“偏要，硬要偏要，硬要”，指做令人不快的事情，指做令人不快的事情dare 和和 need半情态助动词半情态助动词实实义义动动词词肯定式肯定式He dares to escape.He needs to escape.否定式否定式He darent escape.He neednt escape.He doesnt dare(to)escape.He doesn
20、t need to escape.疑问式疑问式Dare he escape?Need he escape?Does he dare(to)escape?Does he need to escape?惯用语惯用语How dare you/he?表达表达“愤怒，谴责愤怒，谴责”之意之意I dare say.我以为，我想我以为，我想He is not here yet,but I dare say he will come later.小结：1.表能力2.表允许3.表推测4.表否定推测can/be able tocan/maymight/may/could/can/should/ought to/w
21、ould/will/mustcant/may not情态动词情态动词+have done这是历年高考热点之一，这是历年高考热点之一，可表示可表示“推测、责备、怀疑推测、责备、怀疑”等多种意义。等多种意义。一、表示对过去事情的推测或估计一、表示对过去事情的推测或估计1.must have done “想必或肯定已经做了某事想必或肯定已经做了某事”eg:The ground is rather wet,so it must have rained last night.2.may/might have done “可能可能/大概已经做了某事大概已经做了某事”eg:Tom may have gone
22、 to shanghai,but I still not sure about it.3.cant/couldnt have done“不可能已经做了某事不可能已经做了某事”eg:The ground is very dry,so it cant have rained last night注：在疑问句中注：在疑问句中 can/could 表示对过去情况的疑问性表示对过去情况的疑问性 推测，推测，“可能已经可能已经了吗？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
23、责备二、表示对过去所发生事情的遗憾或责备1.should/ought to have done“过去本该做而没做过去本该做而没做”eg:I really regretted wasting the hours when I should have studied hard,but it was too late.2.shouldnt/oughtnt to have done “过去不该做的事却做了过去不该做的事却做了”eg:Im very sorry for the words I shouldnt have said to you at that moment.3.could/might h
24、ave done“本来能够做的事却没做本来能够做的事却没做”eg:He could have worked out the problem.He neednt have come.He didnt need to come.他本没有必要来（实际也没来）他本没有必要来（实际也没来）他本没有必要来（实际却来了）他本没有必要来（实际却来了）4.neednt have done“原本不必做的事却做了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.didnt nee
25、d to do/didnt have to do “没有必要做，实际也没做没有必要做，实际也没做”eg:I didnt need to clean the windows.My sister did it.6.would rather have done “本想做却未做成本想做却未做成”eg:I would rather have come to help you with your English,but I was too busy at that time.1.-There were already five people in the car but they managed to t
26、ake me as well.-It _a comfortable journey.A.cant be B.mustnt have been C.shouldnt be D.couldnt have beenD2.The fire spread through the hotel very quickly but everyone _ get out.A.had to B.would C.could D.was able toD4.Peter _ come with us tonight,but he isnt very sure.A.must B.can C.may D.willC5.-Co
27、uld I call you by your first name?-Yes,you_.A.will B.could C.may D.mightC6.Sorry,I m late.I _ have turned off the alarm clock and gone back to sleep again.A.might B.should C.can D.willA7.-Excuse me,but I want to use your computer to type a report.-You _ have my computer if you dont take care of it.A
28、.shant B.might not C.neednt D.shouldntA8.-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.needB9.With so much work on hand,you _to see the game last night.A.mustnt go B.could have goneC.shouldnt go D.shouldnt have goneD10.Johnny,you _play with the knife,you _hurt yourself.A.wont;cant B.mustnt;mayC.shouldnt;must D.cant;wouldntB11.There is no light in the dormitory.They must have gone to the lecture,_?A.didnt they B.dont they C.mustnt they D.havent theyD12.I missed the bus,so I _ go home on foot.A.must B.may C.can D.had toD
