高中英语必修三 5.3 Discovering Useful Structure 教学设计

1、Unit 5 The Value of MoneyPeriod 3 Discovering Useful Structure教学设计The theme of the section is “Express modality and talk about future events in the past”. In the daily conversations, the modal verbs are often used to express our emotions or feelings, attitudes, requirements, order, will, advice, int

2、ention, obligation and possibility, etc. So it is necessary for students to guided to learn modal verbs. The part also involves the past future tense, so the structure “would+do” and “was/were going to+ do” needs paying more attention to, which is used to express the future events took place in the

3、past. The past future tense is similar to the the present future tense, which makes it easier to learn and understand.Learn the definition, structure, functions and features of modal verbs and past future tense.Learn to summarize the usage of modal verbs, especially guessing the past events.Learn th

4、e definition, structure, functions and features of modal verbs and past future tense.Learn to summarize the usage of modal verbs, especially guessing the past events. Part A Modal verbsStep 1 Definition of modal verbsAccording the literal interpretation of modal verbs, we can know that its definitio

5、n is: modal verbs means the speakers tone, emotion or attitude to some kind of action and state, expressing requirement, obligation, intention and so on.(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。)Step 2 Kind of modal verbs原形过去式词义can could能；能够maymight可以；或许；可能must必须；一定是willwould将；将要；愿意shallshou

6、ld应该need需要；必要daredared敢；敢于have tohad to不得不；必须ought to应该used to过去常常Step 3 Functions of modal verbsUnderline the modal verbs in the following sentences and understand its definition and functions.Roderick: Young man, would you step inside a moment, please ?（表委婉请求）Rodercik: If you dont mind, may I ask

7、you how much money you have ?（表委婉请求）Henry: It may seem lucky to you. Now if youll excuse me, I ought to be on my way. （表推测） (表委婉请求)Roderick: You mustnt think we dont care about you. (表推测)May you have good journey!(表祝愿) Summary: 情态动词表示委婉请求，推测、祝愿、建议、意愿、禁止等。Step 4 Basic usage of modal verbs1不能单独作谓语，除ou

8、ght to和used to以外，后面只能接不带to的不定式 2没有人称和数的变化。但有些情态动词，如can，will，dare有一般时和过去时的变化。 3情态动词的“时态”的形式并不是区分时间的主要标志。不少情况下，情态动词的现在时形式和过去时形式都可用来表示现在时间、过去时间或将来时间Step 5 More about modal verbs1can和could (1)表示能力，常译为“能，会” 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“可以”；could还可以表示更加委婉地请求或许可例如： 一C

9、anCould I have a look at your photos?我可以看看你的照片吗? 一0f 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 (3)表示对现在或过去情况的推测，只用于疑问句或否定句中例如： 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 happ

10、en 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call的可能性小)辨析 can(could)/be able to(1)can只有现在时和过去时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一般指自身具有的能力。而be able to则表示经过一段时间的努力后所具有的能力，相当于manage to do或succeed in doing。例如：This time l failed i

11、n 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)She said she regretted not being able to use the computer well她说她很后悔不会很好地使用电脑(3)否定结构中was/were able to 与could没有区别。例如：She ran fast but she couldnt/wasnt able to catch the bus她跑得很快可还是没能赶上公共汽车The young man couldnt carry the big

12、 stone 这个年轻人搬不动那块大石头。(指本身的能力) 2.maymight (1)表示许可或征询对方许可，常译成“可以”。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may或can否定回答时要用mustnt或cantmustnt表示“不可以”“禁止”之意例如： You may go home now现在你可以回家了 May/ Might I have a word with you? 我可以和你谈谈吗? 一May 1 come in? 我可以进来吗?一Yes，you maycan.进来。一No, you cantmustn

13、t你不能。 (2)may常用于祈使句中表示祝愿例如： 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，一般只用于肯定句中，may not表示“可能不”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3will /would (1)表示请求、建议，用于第二人称疑问匀中would比will语气更委婉。例如： Will you call

14、 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“愿；要”之意would表示过去的意愿和决心。例如： 1 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 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。 T

15、he 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may, might, can, could 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 Americ

16、a, judging by his accent.(表_)5. (may/can) _you swim?(表_)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 coole

17、r day.(表_)10. You (can/might) _ be right, but Im going back to check it.(表_)Answers: 1. might 表推测2. may 表许可3. could 表请求4. could 表能力5. can 表能力 6. may not 表不允许7. cant 表推测，不可能8. couldnt 表许可9. could 表推测10. might 表推测 4shallshould (1)shall用于第一、第三人称疑问句中，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?

18、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用于第二、第三人称，表示说话人给对方命令、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) 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

19、(威胁) (3)should表示劝告、建议、命令，其同义词是ought to；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： You 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 (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

20、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如果火车准点的话，她应该7点前到达北京。 5mustcant (1)must表示“必须；必要”用于一般疑问句中，肯定回答用must。否定回答要用neednt或dont have to。例如： Must we hand in our exercise today?我们必须今天上交练习吗? Yes, you must是的，你们必须。 一No, you needntdont have to不，你们不必。 (2)mustnt表示“不允许；禁止”。例如

21、： You mustnt lend the new book to others你不许把这本新书借给别人。 (3)有时must表示“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“一定；肯定”。作此解时，must的否定形式不是mustnt，而是cantcouldnt。例如： They must be anxious to know the result他们一定急于知道结果。 一I think the news must be true 我想这个消息一定是真的一No，it

22、cant be true不，它肯定不是真的。Exercise: 用will, would, shall, should, must 填空1. We _ smoke here, because the worker is 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_)5.Need I

23、 hand in my exercise 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_)Answers: 1. mustnt 表禁止2. should 表建议，命令3. would 过去习

24、惯4. will 表意愿5. must 表必须6. must 表推测7. should 表建议8. will 表将会6need(1) 用作情态动词, need意为“需要, 有必要”, 一般用于否定句或疑问句中。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。 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。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dared。 How

25、 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。Exercise: Must I stay here? No, you _. You _not be told twice about one s

26、ingle thing.Sarah doesnt _ hand in her task right now.How _you fight against him? No one _say he had nothing on.I _ to swim across this river Answers: 1. neednt 2. need3. need4. dare5. dare6. dare8.情态动词+have done (1)can(could)+have done的疑问或否定形式表示对过去发生的行为的怀疑或否定，另外could have done还表示“过去本能够做，但实际上未做”。例如：

27、 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 cancould 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 (2)may(might)+have done表示对过去所发生事情的推测。例如： He may have said so他可能这么说过。 That was too dangerousYo

28、u might have killed yourself那太危险了。你当时可能会丧命的 (3)should+have done表示过去本应该做而实际上未做，而shouldnt+have done表示过去本不应泼做但实际上做了。 例如：You should have started earlier你本应该早点动身。 You shouldnt have lent him money yesterday 昨天你本不该把钱借给他。 (4)must+have done表示对过去发生情况的肯定推测。 例如： It must have rained last night昨晚肯定下雨了Part B The f

29、uture past tenseStep 1 Definition According to the literal interpretation, the definition of the future past tense is: the action or state would take place or happen after a certain past time point, which is often used in the objective clause.（过去将来时表示从过去某一时间来看将要发生的动作或存在的状态, 常用在宾语从句中。）Step 2 Structur

30、ewould/should+dowas/were going to +dowas/were about to +dowas/were to+ dowas/were +doing Other forms:肯定结构would/should+doWas/were going to do否定结构1.wouldnt/shouldnt+do2. wasnt/werent going to do一般疑问结构Would/Should主语doWas/Were 主语 going to do特殊疑问结构特殊疑问词would/should主语do特殊疑问词was/were 主语 going to do She wou

31、ld not go with us.（否定句）Would she not go with us ?(一般疑问句）What would be their ideas?(特殊疑问句） She was going to Beijing.（否定句）Were they going to launch the satellite after that accident ?(一般疑问句）What was Sal going to do if they answered his requirement ?(特殊疑问句）Step 3 Meaning 1. 过去将来时表示从过去某一时间来看将要发生的动作或存在的状态, 常用在宾语从句中。一般由“would/should +动词原形”构成。She hoped that they would meet again someday. 她希望将来有一天他们能再见面。 2. was/were going to+动词原形: 表示过去将要发生或很有可能发生的动作,