英语人教版高中必修三(2019新编)-5

Unit 5 The Value of Money
Period 3 Discovering Useful Structures
情态动词和过去将来时态（导学案）
This teaching period is about expressing modality and talking about future events in the past. Modality reflects the feelings of the person who is talking. It is still a really big challenge for senior students to master the usages of the modal words. Generally, in this unit, we will review and further learn the following model words, would/had better/ ought to/dare/should etc.
As for the structures about the future events, we should lead students to master would be/do; was /were going to do/be about to do.
1. Guide students to review the basic usages of “modality” and talk about future events in the past.
2. Enable students to use the related grammar structures flexibly.
3. Strengthen students’ great interest in grammar learning.
1. Help students to appreciate the function of “modality”and the meanings of the structures “was (were) about to
/was (were) going to do/was (were) going”
2. Instruct students to write essays using the proper “modality”and past future tenses.
指出下列句中画线部分的含义
1．That is why Letters from Father Christmas could be the perfect book.
2．The children must have been very excited as they opened it.
3．They might not receive their presents if they were not good.
4．I was able to hold a knife and fork—and chopsticks！
5．But there are still some dishes that Dad dare not try even after many years of marriage to my mother.
6．Mum and I just have to find a way to get him into the kitchen！
7．we'd better not eat too much roast food as it may make us suffer from heat inside our bodies, ...
8．“You needn't try it if you don't want to，” Mum said.
【答案】：1.能够 2.一定；准是 3.可能 4.能够 5.胆敢，敢于 6.不得不7.最好8.不必
一、情态动词can与could的用法
1．表示能力：can用来表示现在的能力，could表示过去的能力。

I can play basketball now, but I couldn't when I was young.
现在我会打篮球了，但小时候我不会。

2．表示请求和许可：could语气比can委婉，但回答时只能用can。

Can/Could you lend me a hand?
你能帮我一下吗？
3．表示推测，意为“可能”。

多用于否定句或疑问句。

—Can he be in the reading room now?
—No, he can't be in it.Because I saw him in the office just now.
——他现在可能在阅览室吗？
——不，他不可能在(阅览室)。

因为我刚刚在办公室看见他了。

4．表示理论上或习惯上的可能性，意为“可能会”。

Jogging can help you keep fit.慢跑有助于保持身体健康。

二、情态动词may与might的用法
1．表示征求对方的许可或允许(不用might)对方做某事。

—May I come in?
—Yes, you may/can.
——我可以进来吗？
——是的，你可以进来。

(No, you can't.不行，你不能进来。

)
You may go now.
你现在可以走了。

2．表示推测(把握不大)，意为“可能”，多用于肯定句。

might比may可能性更小。

He may come, or he may not.
他可能来，也可能不来。

It may/might rain this afternoon. You'd better take a raincoat with you.
今天下午可能会下雨。

你最好带上雨衣。

3．may用于祈使句，表示祝愿。

May you succeed!
祝你成功！
4．“may/might as well＋动词原形”表示“不妨，还不如”。

I may/might as well start at once.
我还不如马上就动身。

三、情态动词must的用法
1．表示命令或强烈的建议，意为“必须”。

All the students must obey the school rules.
所有学生必须遵守校规。

2．表示十分肯定的推测，意为“一定；准是”。

Betty must be in the next room. I can hear her talking there.
贝蒂肯定在隔壁房间。

我能听见她在那儿讲话。

3．表示说话人的一种态度，意为“偏要；硬要；偏偏”。

Why must he go out in the bad weather?
为什么他偏要在这种坏天气出门？
4．must not表示禁止，意思是“不许”“不准”“不可以”等。

You mustn't stop your car in the busy street.
你不能把车停在繁忙的路上。

5．回答must问句时，肯定回答多用must; 否定回答多用needn't或don't have to。

—Must I finish my homework before eight o'clock?
—Yes, you must.(No, you needn't/you don't have to.)
——我必须要在8点之前完成作业吗？
——是的，必须。

(不，没必要。

)
四、be able to的用法
be able to意为“能够，有能力”，不仅有时态、人称和数的变化，而且还可以与某些情态动词连用(通常不与can 连用)，甚至还可以有非谓语形式。

Since his accident he hasn't been able to leave the house.
自出事之后，他一直未能离开家。

You might be able to persuade him.
你也许能够说服他。

I hope to be able to do the work.
我希望能干得了这项工作。

I regret not being able to help her.
我很遗憾未能帮助她。

[易混辨析：can, be able to表示“能力”时的区别]
Babies can swim when they were born.
婴儿们刚生下来时会游泳。

(自身具有的能力)
Without his hard work, he was not able to get good grades.
如果他没有努力工作，他是不可能取得好成绩的。

(经过努力)
五、dare的用法
dare既可作情态动词，也可作实义动词。

1．dare作情态动词时，表示“敢，敢于”，后跟动词原形，常用于疑问句、否定句和条件句中。

此时的dare没有人称、数和时态的变化，能单独构成否定和疑问。

例如：
Dare you climb that tree?
你敢爬那棵树吗？
He daren't go there because it is very dangerous.
他不敢去那儿，因为那儿很危险。

2．dare用作实义动词时，有时态和人称的变化，用do, does或did来构成否定句或疑问句。

She didn't dare to say a word, did she?
她一句话也不敢说，是吗？
六、have to的用法
have to意为“不得不”，有时态、人称和数的变化，其否定形式为
don't/doesn't/didn't have to。

It's too late. I have to go home now.
天色太晚了，我现在得回家了。

You don't have to finish the work now.
你没有必要现在完成这项工作。

【点津】have to和must的区别：
have to表示一种客观的需要，而must表示一种主观的需要。

此外，must还表示“偏要”“非得”的意思。

I have to attend an important meeting this afternoon.
今天下午我不得不参加一个重要的会议。

I must clean the room because there are too dirty.
因为太脏了，我必须要打扫房间。

七、had better的用法
had better意为“最好；应该”，后跟动词原形，常用来提出建议，或表示迫切的希望、警告等，语气较强。

其中动词had没有人称或数的变化。

had better的简略式为：'d better，否定式为：had better not。

She'd better get here soon or she'll miss the opening ceremony.
她最好快点到这儿来，否则她会错过开幕式的。

They had better not be late.
他们最好不要迟到。

八、need的用法
1．作情态动词
(1)need作情态动词时，常用于疑问句、否定句或条件句中，意为“必须”或“需要”。

—Need I finish the work today?
—Yes, you must. /No, you needn't.
——我需要今天干完这项工作吗？
——是的，必须干完。

/不用，你不必干完。

(2)needn't 意为“不必”，表示客观上不必如何。

There's plenty of time.You needn't drive so fast.
时间很充足，你不必开这么快。

2．作实义动词
need作实义动词时，后可接名词、动名词、不定式等，有人称、时态和数的变化。

The bike needs repairing.
＝The bike needs to be repaired.
这辆自行车需要修理。

过去将来时
过去将来时表示在过去某一时间将要发生的动作或存在的状态。

过去将来时常用在主句谓语动词为过去时态的宾语从句中。

过去将来时句子中有时包含时间状语the next day，soon等。

[观察例句]
1．I was about to get the letter.
2．They said the letter inside would explain what it was all about.
3．The director said he would meet the famous actor the next day.
4．They were going to find someone to take part in their bet when they saw Henry walking on the street outside.
[归纳]
1．过去将来时的基本构成和用法
过去将来时由“would＋动词原形”构成，主要表示从过去某一时间来看将要发生的动作(尤其用于宾语从句中)，还可以表示过去的动作习惯或倾向。

Jeff knew he would be tired the next day.
He promised that he would not open the letter until 2 o'clock.
She said that she wouldn't do that again.
2．表示过去将来时的其他表达法
(1)was/were going to＋动词原形：该结构有两个主要用法，一是表示过去的打算，二是表示在过去看来有迹象表明将要发生某事。

I thought it was going to rain.
(2)was/were to＋动词原形：主要表示过去按计划或安排要做的事情。

She said she was to get married next month.
(3)was/were about to＋动词原形：表示在过去看来即将要发生的动作，由于本身已含有“即将”的意味，所以不再与表示具体的将来时间状语连用。

I was about to go to bed when the phone rang.
(4)was/were＋现在分词：表示在过去看来即将发生的动作，通常可用于该结构中的动词是come，go，leave，arrive，begin，start，stop，close，open，die，join，borrow，buy等瞬间动词。

Jack said he was leaving tomorrow.。