【课件】Unit5语法讲解课件高中英语人教版选择性必修第二册

1、语法精讲语法精讲Unit 5 Definition of modal verbs望文生义，情态动词表示说话人对某一动作和状态的情感态度和语气, 表示“需要、应当、可以、必须等。Kind of modal verbs原形原形过去式过去式词义词义canmaymustwill shallcould能；能够might 无wouldshould可以；可能必须；一定是将(要)；愿意应该无需要；必要daredhad to无无敢；敢于不得不；必须应该过去常常原形原形过去式过去式词义词义needdarehave toought to used toLeading-inMay we ask what youre

2、doing in this country and what your plans are?I cant say that I have any plans.You mustnt worry about that.Could you offer me work here?Read the sentences below and think about:What are the functions and meanings of these modal verbs?may / mightmust / have toshall / shouldwill / wouldought toneed /

3、darecan / couldMindmap of the modal verbs modal verbsModal verbs have many functions, including the following (A-F). A. necessity B. possibility C. obligation D. request E. advice F. intentionUnderline the modal verbs in the following sentences and understand its definition and functions.Functions o

4、f modal verbs1.Roderick: Young man, would you step inside a moment, please ? (表_)2.Rodercik: If you dont mind, may I ask you how much money you have ? (表_)3.Henry: It may seem lucky to you. Now if youll excuse me, I ought to be on my way. (表_) (表_)4.Roderick: You mustnt think we dont care about you.

5、 (表_)_ 委婉请求委婉请求推测委婉请求推测_ _ _ _ 5.May you have good journey! (表_)Summary: 情态动词表示_，_、_、建议、意愿、禁止等。委婉请求祝愿推测_ 祝愿We use modal verbs to talk about A. ability or will（能力或意愿）（能力或意愿） B. prohibition（禁止）（禁止）C. making suggestions（建议）（建议）D. certainty or inference（可能性或推断）（可能性或推断）E. politeness or euphemism（客气或委婉）（客

6、气或委婉）F. obligations or expectations（义务或预期）（义务或预期）1can和和could (1)表示能力，常译为“_” 例如： I can speak Japanese。but I cant write it我会说日语，但是不会写 (2)表示允许，常译为“_”；could还可以表示更加委婉地请求或许可例如： 一CanCould I have a look at your photos?我可以看看你的照片吗? 一Of course you can当然可以了。 You can smoke in this room.你可以在这间屋子里吸烟。能，会 可以 (3)表示对现

7、在或过去情况的_，只用_或_中例如： 一Can she be in the classroom?她可能在教室吗? 一NO，she cant be in it不，她不可能在教室里。 Can what he said be true?他说的可能是真的吗? (4)用于肯定的陈述旬中，表示理论上或习惯上的可能性。例如： Accidents can happen at any time事故随时会发生 It could be very interesting to go out for a drive出去开车兜风可能会很有趣 (could比can的可能性小)推测 疑问句否定句 辨析辨析 can(could

8、)/be able to(1)can只有_时和_时could而be able to则有更多的时态变化，在将来时，完成时和非谓语动词中只能用be able to。(2)can一般指_。而be able to则表示经过一段时间的_后所具有的能力，相当于_或succeed in doing。例如：This time l failed in the exam, but I11 be able to pass the exam next time这次我考试不及格但下次我能考试及格 (经过努力)现在 过去自身具有的能力努力 manage to do2.maymight(1)表示许可或征询对方许可，常译成“

9、_”。表示征询许可时，may 可与cancould换用might比may的语气更委婉一些对其一般疑问句的肯定回答可用_或_否定回答时要用_或_表示“不可以”“禁止”之意例如： You may go home now现在你可以回家了 一May 1 come in? 我可以进来吗?一Yes，you _.进来。一No, you _你不能。可以 maymustntcant canmustntmaycanmustntcant (2)may常用于祈使句中表示_例如： May you succeed!祝你成功! May God bless you l!愿上帝保佑你!(3)表示对现在或过去情况的推测，一般只用

10、于肯定句中，may not表示“_”之意。might比may可能性小 He may be very busy now他现在可能很忙 一Why hasnt he come?他为什么还没来? 一He may have missed the train.他可能没赶上火车吧祝愿 可能不3will /would(1)表示请求、建议，用于第_人称疑问匀中would比will语气更委婉。例如： Will you call back laterplease?请过一会儿再打过来好吗? Would you like a cup of coffee?你想来杯咖啡吗?(2)表示意志、愿望和决心，有“_”之意would

11、表示过去的_和_。例如： I will do my best to help you我愿尽我最大努力帮助你(3)表示习惯性动作或某种倾向。would表示过去习惯性的动作或倾向第二 愿；要意愿决心3will /would Oil will float on water油总是浮在水上 On Sunday he would go to the park to play chess 以前每到星期天他总是到公园去下棋 (4)(表示功用或能力)能。 The room will seat 100 persons 这个屋子能坐下100人。 The door wont open这门打不开Exercise: 用用

12、may, might, can, could 填空填空1. They (can/might) _be away for the weekend but Im not sure.(表_)2. You (may/might) _leave now if you wish.(表_)3. (could/may) _ you open the window a bit, please?(表_)4. He (can/could) _be from America, judging by his accent.(表_)5. (may/can) _ou swim?(表_)might 推测许可请求能力能力may

13、could could can Exercise: 用用may, might, can, could 填空填空6. Listen, please. You (may not/might not) _ speak during this exam.(表_) 7. They (can not/may not) _ still be out, the light is on in the house.(表_)8. You (couldnt/might not) _smoke on the bus.(表_)9. With luck, tomorrow (can/could) _be a cooler

14、day.(表_)10. You (can/might) _ be right, but Im going back to check it.(表_)may not 不允许推测，不可能can not couldnt 许可could 推测might推测4shallshould (1)shall用于_、_人称疑问句中，表示说话人征求对方的意见或向对方请示。例如： What shall we do this evening?我们今晚干什么呢? When shall he be able to leave the hospital?他什么时间能离开医院? (2)shall用于_、_人称，表示说话人给对方

15、命令、警告、允诺或威胁。例如： You shall fail if you dont work hard如果你不努力学习你会考试不及格 (警告) You shall not leave your post你不得离开岗位。(命令)第二 第二第三第一 He shall have the book when I finish reading it 当我读完这本书时他可以拿走 (允许) He shall be punished他将受到惩罚 (威胁)(3)should表示劝告、建议、命令，其同义词是_；在疑问句中，通常用should代替ought to，意为“应该”。(还常用于虚拟语气中) 例如： Yo

16、u shouldnt have left so soon. 你不应当走得这么早 Sal suggested that we should go for a swim 萨尔建议我们去游泳ought to (4)should表示推测，可能。这种推测往往有一定的根据。含有“按道理应当”之意。例如： They should be at home by now for they have been away for two hours现在他们该到家了，因为他们离开两个小时了 If the train is on time，she should arrive in Beijing by seven如果火车

17、准点的话，她应该7点前到达北京。 5mustcant(1)must表示“_”用于一般疑问句中，肯定回答用_。否定回答要用_或_。例如： _ we hand in our exercise today?我们必须今天上交练习吗? Yes, you_是的，你们必须。 一No, you _不，你们不必。(2)mustnt表示“_”。例如： You mustnt lend the new book to others你不许把这本新书借给别人。必须；必要 mustdont have toMust mustntmustneedntdont have to不允许；禁止 5mustcant(3)有时must表示

18、“偏要；硬要；偏偏”，指做令人不快的事情。例如： Must you shout so loudly? 你非要这么大声嚷嚷吗?(4)must表示推测时。只能用于肯定句，意为“_”。作此解时，must的否定形式不是mustnt而是_。例如： 一I think the news _true 我想这个消息一定是真的 一No，it _ true不，它肯定不是真的。一定；肯定 cant/couldntmust becant beExercise: 用用will, would, shall, should, must 填空填空1. We _ smoke here, because the worker is

19、 carrying some petrol.(表_)2. It is dangerous. You _ leave the room immediately. (表_)3. He _ go hiking with friends at weekends when young. (表_)4. Write to me when you get home. -I _.(表_)mustnt禁止建议，命令would意愿should过去习惯will Exercise: 用用will, would, shall, should, must 填空填空5. -Need I hand in my exercise

20、 book at once? -Yes, you_.(表_)6. You have been working all day. You _be very tired. (表_)7. It is a long time since we met last time. You _ come and see us more often.(表_)8. Why dont you try on this dress? It _ look nice on you.(表_)must 必须推测must should 建议will将会 6need(1) 用作情态动词, need意为“_”, 一般用于否定句或疑问句

21、中。疑问句中把need提前, 否定形式是在need后加not。 You neednt come here this afternoon. 你今天下午不必来。(2) 用作实意动词, 意为“需要, 有必要”, 可以用于各种句式中。 You dont need to go now. 你不必现在就走。需要, 有必要 7dare(1) dare作情态动词时, 常用于疑问句、否定句和条件从句中, 过去式形式为_。 How dare you say Im unfair? 你怎么敢说我不公平? He darent speak English before such a crowd, dare he? 他不敢在

22、这么多人面前说英语, 是吗? (2)dare作实义动词用时, 有人称、时态和数的变化。在肯定句中, dare后面常接带to的不定式。在疑问句和否定句中, dare后面可接带to或不带to的不定式。 He doesnt dare (to) answer. 他不敢回答。dared Exercise: 用用need, dare 填空填空1.Must I stay here? No, you _. 2.You _not be told twice about one single thing.3.Sarah doesnt _ hand in her task right now.4.How _you

23、fight against him? 5.No one _say he had nothing on.6.I _ to swim across this riverneednt needdareneed daredare8.情态动词情态动词+have done (1)can(could)+have done的疑问或否定形式表示对_发生的行为的_或_，另外could have done还表示“_”。例如： He cantcouldnt have finished so much work in so short a time 他不可能在这么短的时间内完成如此多的工作。 Where cancoul

24、d they have gone? 他们会到哪去了呢? We could have gone there on footA taxi wasnt necessary at a11 本来我们可以走着去那儿根本没有必要乘出租车过去 怀疑 否定 过去本能够做，但实际上未做 (2)may(might)+have done表示对过去所发生事情的推测，表示 “_”。例如： He may have said so他可能这么说过。 That was too dangerous。You might have killed yourself那太危险了。你当时可能会丧命的 (3)should+have done表示

25、过去 “_”，而shouldnt+have done表示过去 “_” You should have started earlier你本应该早点动身。 You shouldnt have lent him money yesterday 可能做过. 本应该做而实际上未做本不应泼做但实际上做了 (4)must+have done表示对过去发生情况的肯定推测， 表示 “_” 例如： It must have rained last night昨晚肯定下雨了一定做过. In the film The Million Pound Bank Note, Henry Adams is stuck in a

26、 foreign country without money and friend and with nowhere to stay. While this situation _ seem unusual, it can sometimes happen to travelers. In case it happens to you on a trip abroad, what _ you do? First, and most importantly, you _ stay calm. Fear _ cause you to become confused. You need to thi

27、nk clearly. Second, you should go to your nearest consulate. They _ be able to help to some extent. Third, you _ do well to check with some local charities. They _ offer help to travelers in need. Fourth, you _ avoid getting into trouble. You _ think that stealing some money or food would help you, but you should not