英语人教版高中必修三(2019新编)-5

Unit 5 The Value of Money
Period 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, intention, 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 past. The past future tense is similar to the the present future tense, which makes it easier to learn and understand.
1.Learn the definition, structure, functions and features of modal verbs and past future tense.
2.Learn to summarize the usage of modal verbs, especially guessing the past events.
1.Learn the definition, structure, functions and features of modal verbs and past future tense..
2.Learn to summarize the usage of modal verbs, especially guessing the past events.
Part A Modal verbs
Step 1 Definition of modal verbs
According the literal interpretation of modal verbs, we can know that its definition is: modal verbs means the speaker’s 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
Step 3 Functions of modal verbs
Underline the modal verbs in the following sentences and understand its definition and functions.
1.Roderick: Young man, would you step inside a moment, please ?（表委婉请求）
2.Rodercik: If you don’t mind, may I ask you how much money you have ?（表委婉请求）
3.Henry: It may seem lucky to you. Now if you’ll excuse me, I ought to be on my way.
（表推测）(表委婉请求)
4.Roderick: You mustn’t think we don’t care about you. (表推测)
5.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 verbs
1．不能单独作谓语，除ought 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 verbs
1．can和could
(1)表示能力，常译为“能，会” 例如：
I can speak Japanese。

but I can’t 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：
①一Can／Could 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。

②You 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：
①一Can she be in the classroom?她可能在教室吗?
一NO，she can’t be in it．不，她不可能在教室里。

②Can 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：
①Accidents can happen at any time．事故随时会发生
②It 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：
①This time l failed in the exam，but I’11 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)
②She 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：
①She ran fast but she couldn’t/wasn’t able to catch the bus．她跑得很快可还是没能赶上公共汽车
②The young man couldn’t carry the big stone．这个年轻人搬不动那块大石头。

(指本身的能力)
2.may／might
(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can／could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mustn’t 或can’t．mustn’t表示“不可以”“禁止”之意例如：
①You may go home now．现在你可以回家了
②May/ Might I have a word with you? 我可以和你谈谈吗?
③一May 1 come in? 我可以进来吗?
一Yes，you may／can.进来。

一No, you can’t／mustn’t．你不能。

(2)may常用于祈使句中表示祝愿例如：
①May you succeed!祝你成功!
②May 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
①He may be very busy now．他现在可能很忙
②一Why hasn’t 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
3．will /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：
①Will you call back later．please?请过一会儿再打过来好吗?
②Would 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
①Oil will float on water．油总是浮在水上
②On 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。

①The room will seat 100 persons．这个屋子能坐下100人。

②The door won’t open．这门打不开
Exercise: 用may, might, can, could 填空
1. They (can/might) ___________be away for the weekend but I’m 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) ___________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 (couldn’t/might not) _________________ smoke on the bus.(表________)
9. With luck, tomorrow (can/could) __________be a cooler day.(表________)
10. You (can/might) ___________ be right, but I’m 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. can’t 表推测，不可能
8. couldn’t 表许可9. could 表推测10. might 表推测
4．shall／should
(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：
①What shall we do this evening?我们今晚干什么呢?
②When 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：
①You shall fail if you don’t work hard．如果你不努力学习你会考试不及格(警告)
②You shall not leave your post．你不得离开岗位。

(命令)
③He shall have the book when I finish reading it．当我读完这本书时他可以拿走(允许)
④He 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：
①You shouldn’t have left so soon. 你不应当走得这么早
②Sal 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：
①They 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
②If 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。

5．must／can’t
(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needn’t或don’t 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 needn’t／don’t have to．不，你们不必。

(2)mustn’t表示“不允许；禁止”。

例如：
You mustn’t 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mustn’t，而是can’t／couldn’t。

例如：
①They must be anxious to know the result．他们一定急于知道结果。

②一I think the news must be true．我想这个消息一定是真的
一No，it can’t 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 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 don’t you try on this dress? It _________ look nice on you.(表________)
Answers: 1. mustn’t 表禁止 2. should 表建议，命令 3. would 过去习惯
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
6．need
(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 needn’t 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 don’t need to go now. 你不必现在就走。

7．dare
(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 dare you say I’m unfair? 你怎么敢说我不公平?
He daren’t 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 doesn’t dare (to) answer. 他不敢回答。

Exercise:
1.—Must I stay here? —No, you _______.
2.You _____not be told twice about one single thing.
3.Sarah doesn’t ______ hand in her task right now.
4.How ____you fight against him?
5.No one ____say he had nothing on.
6.I _____ to swim across this river
Answers: 1. needn’t 2. need 3. need 4. dare 5. dare 6. dare
8.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：
①He can’t／couldn’t 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。

②Where can／could they have gone? 他们会到哪去了呢?
③We could have gone there on foot．A taxi wasn’t 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：
①He may have said so．他可能这么说过。

②That 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表示过去本应该做而实际上未做，而shouldn’t+have done表示过去本不应泼做但实际上做了。

例如：①You should have started earlier．你本应该早点动身。

②You shouldn’t 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 future past tense
Step 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 Structure
1.would/should+do
2.was/were going to +do
3.was/were about to +do
4.was/were to+ do
5.was/were +doing
Other forms:
She would 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, 常用于口语中, 表示预言、意图或者打算等。

He was going to start work the following week. 他打算下星期开始工作。

3. was/were about to do: 常用来表示即将发生的动作, “刚要/正要做……”。

注意该结构不与任何时间状语连用。

I felt that something terrible was about to happen. 我感到某种可怕的事情即将发生。

4.was/were to do: 表示“曾计划做某事”, 如果表示“本来计划做某事, 动作没实现”, 则需用“was/were to have done”。

She said she was to have told me about the accident. 她说她本来想告诉我关于事故的事。

5.Start, go, come, leave, see, meet等动词的过去进行时: 表示就过去某一时刻而言即将发生的动作。

She was coming later. 她随后就来。

I had just put on my overcoat and was leaving to visit a friend of mine.
我刚穿上外套要去看我的一个朋友。

Step 4 Exercise
Complete the sentences with the correct forms.
1.She said the bus __________(leave)at five the next morning.
2.I wasn’t sure whether he __________(lend)me his book the next morning.
3.At that time he did not know that quitting the job _____________(become) the turning point in his
life.
4.He said he _______________(visit) China the next week.
5.In his introduction, he made it clear that our credits ________(be) hard-earned.
Answers: 1. was leaving 2. would lend 3. was to become 4. was going to visit
5. would be
Step 5 Homework
Finish the items on Page 54.。