Grammar and usage(1): Modal verbs: general introduction优秀教案内容

情态动词

一、特征

1) 情态动词本身有词义,表示说话人的语气或情态,但词义不完全,不能单独作谓语动词,只能和不带to的动词不定式(ought等除外) ，即动词原型一起构成谓语动词。

2) 情态动词所表示的情态有: 命令、允许、请求、拒绝、愿望、愿意、义务、必要、可能、敢于、需要等。

二．形式变化

情态动词没有人称和数的变化,

第三人称单数的现在时也无变化。

有些情态动词有过去式, 。如：

can – could; shall – should

will- would;

may- might 三. 情态动词的种类

要运用好情态动词，就要首先对情态动词有一个完整的认识，情态动词分为三种情况：

1. 只用作情态动词的有：must, can / could, may / might, ought to 2. 既可作情态动词又可作实义动词的有：need, dare，have /had to, used to 3. 既可作情态动词又为助动词的有：shall / should / will / would 四. 基本用法

1. can, could

a. 表示体力或脑力方面的

“能力”,或根据客观条件能做某种动作的

“能力”。

b. 用于疑问句中表示

许可和请求。could比can 语气更委婉。

c. 用于否定句和疑问句中表推测，意为“不可能”。

d.表示客观的可能性，理论时的可能性，意思是“有时候可能会”

(1) I don’t think he can solve the problem without any help.

(2) Can you help me to work out this

maths problem? (3) Can this be done by him? (4) Even experienced teachers can make mistakes. 2. may, might

a. may 表示

“允许” 或

“请求”，

在口语中可用can替代, 但may比较正式。

b. 表推测, 表示

“或许” 或

“可能” ，一般用于肯定句和否定句；might比may语气更委婉或更加不肯定；

c. “May +主语+动词原形”表示祝愿。

d. might 还可以用于让步状语从句中，意为“尽管”

（1）You may go with us if you like.

_May I smoke here?

_No, you mustn’t./you better not.

（2）He may not come today.

He might have taken your dictionary by mistake （3）May our friendship live long. （4）Try as he might, he still failed. 尽管他努力了，但还是没及格。

3. must

a. 表示说话人的主观看法，意为“必须” 或

“应当”。

b. 表示

“禁止，不许可” 或

“不应该”, 用于否定句，语气比较强烈。

c. 表示说话人对事物的推测, 常用于肯定句，意思为

“一定” 或

“准是”, 语气比may要强得多。

must be

一定是

must have done

过去一定干过某事

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d.表示“偏偏，偏要”，指不愉快的事情。

4. have to

表示客观的需要。意为

“不得不”,并有时态的变化

has to/had to 。

（1）We must do everything step by step. （2）_ Must I water the young trees today?

_No, you needn’t.

（3）You mustn’t play football in the streets. It’s dangerous.

（4）He must be a student, isn’t he?

It must have rained last night, for the ground is wet now. （5）John, look at the time. Must you play the piano at such a late hour? （6）I have to go over my lessons , the exam is coming. 5. shall

a.

用于主语为第一或第三人称的疑问句中,表示说话人征求对方的意见或向对方提出请示。

b. 作情态动词在陈述句中用于第二和第三人称, 表示说话人给对方的

“命令” “警告” “许诺” “威胁” “强制”等。

c. 用于条约，规定，规章等文件中表示一种义务，多用于第三人称。

（1）Shall I open the window?

Shall he come to see you? （2）Tell him that he shall have the book after I read it.

You shall be sorry for what you have done. （3.）The interest shall be divided into five parts according to the agreement made by both sides ,declared the judge.

法官宣布：按照双方协议，利息应分成5个部分。

6. should

a. 表示义务或责任，译为

“应当”。

b. 表示说话人的感情如

“惊奇” “愤怒” “失望” “不满”等。

c. 表推测，should have done sth=ought to have done sth 本应该做某事（事情未做）shouldn’t have done sth=oughtn’t to have done sth 本不应该做某事（事情已做）

（1）You should respect your parents.

You should say sorry to him. （2）I’m surprised that she should get so angry.

（3）You should have told him about it earlier.

You shouldn’t have told David what Mike told you.

7. will

a. 作情态动词用时在陈述句中可用各人称作主语, 表示其

“意志” “意愿”

“决心”等。

b. 在疑问句中用第二人称作主语, 表示说话人向对方提出请示或询问。

c. 有时表示一种习惯动作或状态或自然规律。译为“总是，老是，习惯于”

8. would

a. 可用于各人称, 表示过去时间的

“意志” “愿望” 和

‘决心”。

b. 表示说话人本身的

“意志” 或向对方提出

“请求’。

c.

还可以表示过去习惯发生的动作。

（1）I will do anything for my friends. （2）Will /Would you open the door for me, please? （3）When we were children we would go skating every winter.

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He told me that the box wouldn’t open.

几组情态动词之间的区别

1. can / be able to can 的形式只有can/could两种。

be able to 的形式有am/is/are able to; was/were able to;

have/has been able to等多种。

can 表示一般能力。

be able to 表示经过努力后而达到的一定境界。

My brother can play table tennis. My brother is able to dive under water for 10 minutes. 2. shall / will shall表示允诺; will表示决心或决定。

Don’t worry. You shall have the tickets for the games.

Liu Mei will go and buy the tickets for the games. 在疑问句中，shall用于第一人称或第三人称后，表示提供帮助或给出建议；will用于第二人称或第三人称后，表示询问意愿。

Shall we go swimming this weekend? A group of students are waiting to see you outside. Shall they come in? Will you go hiking with me in the mountains? Will he pay for me ? 3. mustn’t / needn’t

mustn’t 表示“不准，不许”，语气强烈。

needn’t 表示“不需要，没必要”，语气缓和。

You mustn’t miss this football match. It’s very important.

You needn’t watch the game if you don’t want to.

Must we clean the classroom? Yes, you must. /No, you needn’t.

4. need /dare 1.作情态动词，常用于否定句和疑问句中，

Sb needn’t do sth 某人没有必要做某事

Need sb do sth? 某人有必要做某事吗？

Sb daren’t do sth

某人不敢做某事

Dare sb do sth

某人敢做某事吗？

（1）

_Need he do it at once?

_Yes, he must./ No, he needn’t. （2）You needn’t have taken a taxi here; it’s so near. （3）She dare not say what she thinks. （4）I dare say.是习语, 意思是“我相信，可能”

I dare say there are mistakes here. 2.作实义动词时，有词形变化，用于肯定句，否定句和疑问句，

Sb needs to do sth

某人需要做某事

Sb needs sth Sb dares to do sth

某人敢做某事

Sb doesn’t /didn’t need to do sth

某人没有必要做某事

Sb doesn’t /didn’t dare to do sth

某人不敢做某事

Does/Did sb need/dare to do sth?

某人需要/敢做某事吗？

（1）He needs some help.

（2）I don’t need to buy a computer. （3）My watch needs repairing.

（4）How dare you say I’m unfair ? （5）Do you dare to answer these questions openly?

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（6）She dares to walk in the street alone at midnight. （7）We don’t dare（to）say anything. 总结：

1.表示征求对方意见，建议，意愿，许可：

第一人称：

Can/ Could/ May/ Might/ Should / Shall

I 第二人称：Will /Would you 第三人称：Shall/Will/Should he 2.表推测：

现在：must 一定

can 可能

may/might

也许

过去：

must have done sth 过去一定做过某事

might have done sth

过去也许做过某事

could have done sth

过去有可能做过某事

couldn’t have done sth

过去不可能做过某事

3.表说话者的语气：

should have done sth 本应该做某事

shouldn’t have done sth

本不应该做某事

could have done sth 本来可以做某事

needn’t have done sth 本来没有必要做某事

Shall 用在主语是第一人称或第三人称的疑问句中，表示征求对方的允诺。

Shall 用在主语是第二人称或第三人称的陈述句时，表示说话人给对方命令，警告，允诺，决心，威胁的语气。

Shall 用于条约，规定，规章等文件中表义务，用于第三人称。

情态动词的习惯用法:

1.cannot …too/enough 表示“无论怎样也不为过”；“越…越好”。

2.cannot but do sth 表示“不得不，只好”。

3. How dare you …?表示“愤怒，谴责”之意，不表示疑问。

4.may/might as well do sth

还不如做某事，不妨做某事

（1）You can’t be too careful while driving.

（2）You cannot remember enough English words.

（3）He cannot but agree.

（4）

How dare you call him a liar 说谎的人? （5）It’s very late, so you may/might as well go to bed.

Practice

1. I thought you _____like something to read, so I have brought you some books.

A. may

B. might

C. would

D. must

2. A computer ______ think for itself; it must be told what to do. A. can’t

B. couldn’t

C. may not

D. might not 3. They will ______ run this machine on their own in three months.

A. can

B. could

C. may

D. be able to 4. That big cinema ______ seat 2,000 people.

A. can

B. should

C. ought to

D. is able to 5. — Could I borrow your dictionary?

— Yes, of course you _______.

A. might

B. will

C. can

D. should 6.

— Might I watch TV after supper?

— Yes, you ________.

A. may

B. must

C. might

D. can

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7. You ______ return the book now. You can keep it till next week if you like.

A. can’t

B. mustn’t

C. needn’t

D. may not

8. Johnny, you ______ play with the knife. You ______ hurt yourself.

A. won’t; can’t

B. mustn’t; may

C. shouldn’t; must

D. can’t; shouldn’t

9. —Will you stay for lunch?—Sorry, _____. My brother is coming to see me.

A. I mustn’t

B. I can’t

C. I needn’t

D. I won’t

10. —May I pick a flower in the garden?

— ________.

A. No, you needn’t

B. Not, please C. No, you mustn’t

D. No, you won’t

11. —Sir, ____ he go or stay?

—Let him go.

A. will

B. shall

C. might

D. could 12. Ronald ______ stay in his small garden for a long time every day in the past.

A. could

B. might

C. should

D. would 13. Put on more clothes. You_______ be feeling cold with only a shirt on.

A. can

B. could

C. must

D. would 14. ---Must I drive to his house and pick up the children? ---No, _______.

A. you shouldn't B. you might not

C. you needn't

D. you mustn't 15. There is someone knocking at the door. __________ it be Tom?

A. Can

B. Must

C. Should

D. Ought to

16. Two years ago, my husband bought me a bicycle. If you live in town, it is often faster than a car and you_________ worry about parking.

A. must not

B. may not

C. should not D. don't have to

17. — _______I water the trees on Tuesday?

— No, you needn’t.

A. Can

B. Must

C. May

D. Shall

18. He _____ not pay unless he is punished to pay.

A. shall

B. will

C. can

D. would 19. I _____ such a mistake again.

A. shall never make

B. may never make C. can never do

D. need never make 20. —_____ I turn on the radio? __You’d better not. It is noisy enough in this room.

A. Shall

B. Must

C. Need

D. Do

21. Since the road is wet this morning, _____ last night.

A. it must rain

B. it must have rained

C. it must be rained

D. it must have been rained 22. —What does the sign over there read? —“No person _____ smoke or carry a lighted cigarette, cigar or pipe in this area.”(四川

2007) A. will

B. may

C. shall

D. must 23. —How’s your tour around the North Lake? Is it beautiful?

—It _____ be, but it is now heavily polluted. (宁夏

2007) A. will

B. would

C. should

D. must 24. We hope that as many people as possible _____ join us for the picnic tomorrow.

(2006 全国卷II) A. need B. must

C. should

D. can

25. —Must he come to sign this paper himself?

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—Yes, he _____. (广东

2006) A. need

B. must

C. may

D. will 26. John, look at the time. _____ you play the piano at such a late hour? (2005 全国卷III) A. Must

B. Can

C. May

D. Need 27. Tom, you _____ leave all your clothes on the floor like this!

(2005 全国卷I) A. wouldn’t

B. mustn’t

C. needn’t D. may not 28. If I _____ plan to do anything I wanted to, I’d like to go to Tibet and travel through as much of it as possible.

(湖北

2005) A. would

B. could

C. had to

D. ought to 29. —Lucy doesn’t mind lending you her dictionary.

—She _____. I’ve already borrowed one.

(湖南

2005) A. can’t

B. mustn’t

C. needn’t

D. shouldn’t

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