Modal Verbs 情态动词

Modal Verbs 情态动词

(A) : 情态动词的基本用法: (1) 后接动词原形(2). 否定句: 后加not (3). 疑问句: 提前

(1). We should care for others.

(2). I can not swim.

(3). May I come in?

一..can, could

1. 表能力: 能, 会

(1). Can you speak English? (2). I can’t swim.

2. 表许可: 可以

(1). Can I use your telephone? Yes, you can. No, you can’t.

Could I use your telephone? Yes, you can. No, you can’t. (could 语气委婉)

(2). You can’t park your car here. (不可以)

3. 特殊句式

(1). can not/never…too…或can’t…enough越…越好, 无论怎样也不过分

You can’t be too careful. 越认真越好.

You can’t work too hard. 工作越努力越好.

I can’t thank you enough. 感激不尽.

(2). can’t help doing sth., 情不自禁can’t but do

He couldn’t help crying.

When a close friend dies, you can’t but feel sad.

can 与be able to 的区别

(1). 时态: can只有一般现在时can 和过去时could, 而be able to 有各种时态

(2). 主语: can 的主语指人也指物, 而be able to 只指人

二. may, might

1. 表许可

May I come in? Yes, you may. No, you mustn’t.

Might I come in? Yes, you may. No, you mustn’t. (语气委婉)

2.表祝愿

May you succeed. May you live to 100 years. May God be with you. (愿上帝保佑你.)

3. 用于目的状语从句和让步状语从句中

(1). He speaks English slowly so that (in order that) his students may (can) follow him.

(2). Whatever he may say, I don’t believe hime.

4. 特殊结构may/might as well do sth. 还是做…的好

You may as well go to Beijing next Monday.

Since we have nothing to do, we may as well go for a walk.

三. must

1. 表命令, 义务: 必须, 必要

(1). Must I go now? Yes, you must. No, you needn’t.

(2). You must do as you are told.

(3). Cars mustn’t be parked here.

mustn’t 不准, 不允许, needn’t 不必, 没必要

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2. 表必然性: 不免, 肯定

(1). All men must die.人不免一死.

(2).Careless reading must give but poor results.读书不用功, 成绩肯定不好.

3. 表固执: 硬要, 偏要

Why must you be so stubborn? 你为什么偏要这么固执呢?

If you must know why, I’ll tell you the reason.

四. shall

1. 用于第一人称的问句, 征求对方的意见或指示

(1). Shall I shut the door? Yes, please.

对比

May I have a look? 我可以看一下吗? Yes, you may.

Shall I have a look? 我看一下好吗? Yes, please.

2. 用于二, 三人称, 表命令, 允若, 警告, 决心

(1). You shall (must) go to the front前线at once. (命令)

(2). Don’t worry. You shall get the answer this afternoon. (允若)

(3). He shall be sorry one day. I tell you. (警告)

(4). Nothing shall stop us from fighting against pollution. (决心)

3. 用于法律, 条文中

(1). The fine shall be given in cash.罚款应以现金交纳.

(2).It shall be unlawful for any person to keep any wild animal in captivity.

任何人圈养任何野生动物都是违法的.

五.should

1. 表义务, 责任: 应该

You should apologize to him.

We should attend the meeting.

2. 表惊讶, 遗憾: 竟然, 居然

(1). I’m surprised that you should speak in such a way.

(2). I’m glad that your story should win the first prize.

3. 用于疑问句, 表惊讶: 究竟是, 到底

(1). Why should you think that way?

(2). Who should come in? but my friend betty!我当是谁进来了呢, 原来是我的朋友Betty.

4. 用于条件状语从句(虚拟语气)中: 一旦, 万一

(1). If she should know the truth, she would be greatly depressed. (失望)

(2). If you should change your mind, let us know.

(3). She gave me a list just in case I should forget what to buy.

(4). He ran away for fear that he should be caught.

六. would

1. 表过去常常

(1). When I was a child, I would go swimming.

(2). Should come to me just when I was busy.

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2. 表请求, 语气委婉

(1). Would you take a seat?请你坐下好吗?

(2). Would you mind my opening the window?

3. 用于表将来的虚拟语气中; 愿意, 乐意

If you would go there instead of me, I should (会) be very glad.

4. 用于否定句中, 表事物暂时的特性: 就是不

The window wouldn’t open.

My car wouldn’t start.

(B). 情态动词表推测

must 可能性最大: 肯定, 一定

should: 应该会, 一定会, 很可能, 表将来Array can/could : 有时候会(用于肯定句), can/could 一般用于疑问句和否定句

may :也许(语气不肯定)

might: 可能性最小, 也许(语气不肯定)

would : 大概是, 可能是, 似乎是

(一). 情态动词+动词原形: 对现在或将来推测( 疑问句和否定句只能用can ,could)

(1). It’s already 12:30. You _________ be hungry now.

(2). The light is still on. He _________ be working in the office now.

(3). He is always hunting the lions, so terrible things _________ happen to him.

(4). ---Where are you now?

--- I’m on the bus. I __________ be back in ten minutes.

(5). Jogging (慢跑) __________be harmful for the health.

(6). London __________ be rather cold in summer while I stayed there for years.

(7). Mr. Bush is on tine for everything. How _________ it be that he was late for the opening ceremony?

(8). Michael __________ (not) be a policeman, for he’s too shout.

(9). He _________ be in the classroom. I’ll go and make sure.

(10). ---Are you coming to Jeff’s party?

---I’m not sure. I _________ go to the concert instead.

(11). That ________ be in spring 1964.

(12). I __________ be about ten when my brother left home.

(二). 情态动词+have done 表对过去的推测

1. must have done (一定, 肯定)

I didn’t hear the phone. I must have been asleep.

2. may/might have done (也许, 可能)

Tom hasn’t come back yet. He may have missed the bus again.

Sorry I’m late. I might have turned off the alarm clock and goneback to sleep again.

3. can’t/couldn’t have done (不可能)

Jack can’t have arrived yet; otherwise he would have telephoned me.

My sister met him at the Grand Theater yesterday afternoon, so he couldn’t have attended your lecture.

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(三). 情态动词表责备

1. should (ought to) have done 过去该做的而没有做

should not (ought not to ) have done 过去不该做的而做了

(1). We should have studied last night, but we went to the concert instead.

(2). We shouldn’t gone to the concert last night, because we had much homework to do.

(3). They ought not to have let you out of hospital so soon; otherwise, you would feel better.

2. could have done过去本来可以做而没有做

---I didn’t go to class last night because my car broke down.

---You could have borrowed mine. I wasn’t using it.

3. might have done 过去本来会而没有

You are lucky enough. You might have been killed like that.

4. needn’t have done 过去本来没必要做而做了

They needn’t have hurried because there were much time left.

Exercises

1 .---Is the North Lake beautiful?

---It _____ be, but it is now heavily polluted.

A. will

B. would

C. should

D. must

2. --- What does the sign read?

--- “No person _____ smoke in this area.”

A. A. will

B. may

C. shall

D. must

3. She looks very happy. She _____ have passed the exam.

A. should

B. could

C. must

D. might

4. ----Where is my dictionary? I remember I put it here yesterday.

----You ______ it in the wrong place.

A. must put

B. should have put

C. might put

D. might have put

5. I told your friend how to get to the hotel, but perhaps I _____ have driven her there.

A. could

B. must

C. might

D. should

6. ---Turn off the TV, Jack. ______ your homework now?

=== Mum, just ten minutes, please.

A. Should you be doing

B. Shouldn’t you be doing

C. Couldn’t you be doing

D. Will you be doing

7. My MP4 player isn’t in my bag. Where _____ I put it?

A. can

B. must

C. should

D. would

8. ----My cat is really fat.

-----You __________ have given her so much food.

A. wouldn’t

B. couldn’t

C. shouldn’t

D. mustn’t

9. There is no light on. They ______ be at home.

A. can’t

B. mustn’t

C. needn’t

D. shouldn’t

10. We _______ have proved great adventures, but we have done the greatest march ever made in the past ten years. A. needn’t B. may not C. shouldn’t D. mustn’t

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