FillingFilling

1. They ______ go anywhere they wished.2. You _________ go on those ships.3. There _______ be any other foreigners.4. We just ________ show our passports.5. We ______ see the sun setting behind the

white pagoda.

couldshouldn’t

won’thad to

could

Indicate

an ability to do something

use to give advice

make a prediction about the future

the past form of must

the permission to do something

could(1)shouldn’t

won’t

had tocould(5)

Modal Verb

Correction Correction Correct the mistakes and say why.Correct the mistakes and say why.

• John shoulds go to school on time.

• At that time we thought we musted hand i

n our paper.

• You must to finish your homework in time.

• We don’t can be there tomorrow.

• They should may do that.

should

must

can’t

should / may

Observation Observation • Two eyes can see more than one.• I am so strong that I can lift this stone.• He said that Jack couldn’t finish his

work in such a short time.•Could you follow my step?• He is only four, but he is able to read.• She was able to do it without my help.•Will you be able to come to my party

tomorrow?

表能力表能力can

could

be able to 有时态变化有时态变化

Observation Observation • You can go now.

• I won’t let you down.

•Could I say it in Chinese?

•May I know your name?

•Would you mind closing the door?

•Shall we dance?

•Might I have a word with you?

语气

强

弱

表许可表许可 ,, 征征询意见询意见

can, will

could / may / would / shall / might

ObservationObservation • There must be a mistake.

• You may walk ten miles without seeing a house.

• He might get there on time.• It can be true.• In those days few workers could

support their families.

表可能性表可能性(( 猜测猜测 ))

must

may, might, can, could

肯定句

语气

强

弱

ObservationObservation

语气

强

弱• She can’t be serious.

• We couldn’t have done better.

• People may not pick flowers in this garden.

• She was afraid they might not like the idea.

表不可能表不可能(( 猜测猜测 ))

can’t, couldn’t

may not, might not

否定句

ObservationObservation

mustn’t, shouldn’t

had better not

• We mustn’t waste our time.

• They shouldn’t left so soon.

• You’d better not disturb him.

表禁表禁止止

Observation Observation • You should do what your parents tell you.

• If you can’t finish the book by then, you must

come and renew it.

• This is a lovely party, but we have to go

because of the baby-sister.

• The bridge was not wide enough so that

somebody had to give way.

should, must

have to

表义务表义务(( 应该应该 )) 有时态变化

can 和 be able to

1.can/could 表示能力，可能。 只用于现在式和过去式 (could) 。

2.be able to 可以用于各种时态。They will be able to tell you the news soon.

3.用于过去时， could 常表示能够做某事 , 事实上不一定去做was / were able to 设法做成某事

相当于 managed to do sth. succeeded in doing sth.

1.can/could 表示能力，可能。 只用于现在式和过去式 (could) 。

2.be able to 可以用于各种时态。They will be able to tell you the news soon.

3.用于过去时， could 常表示能够做某事 , 事实上不一定去做was / were able to 设法做成某事

相当于 managed to do sth. succeeded in doing sth.

He could swim across the English Channel. But he didn’t feel like it that day. Yesterday I was able to get home before the heavy rain.  

表示允许或请求；没有把握的推测。may 放在句首 , 表示祝愿。

May God bless you!might 表示推测时 , 不表示时态 , 只是可能 性比 may 小。

He may/might be at home.

They might be having a meeting, but I’m not sure.

表示允许或请求；没有把握的推测。may 放在句首 , 表示祝愿。

May God bless you!might 表示推测时 , 不表示时态 , 只是可能 性比 may 小。

He may/might be at home.

They might be having a meeting, but I’m not sure.

may 和 might

have to 和 must  “ 必须” 1. have to 表示由于客观因素不得不做 must 表示说话人的主观意志 , 看法

1.My brother was very ill, so I had to call the doctor in the middle of the night.

2.He said that they must work hard.

1.My brother was very ill, so I had to call the doctor in the middle of the night.

2.He said that they must work hard.

2. have to 有人称、数、时态的变化，而 must 只有一种形式。 He had to look after his sister yesterday.3. 否定结构中 don’t have to 表示“不必” mustn’t 表示“禁止” You don’t have to tell him about it. 　 你没必要把此事告诉他。 You mustn’t tell him about it. 　　　　 你一定不要把这件事告诉他。

2. have to 有人称、数、时态的变化，而 must 只有一种形式。 He had to look after his sister yesterday.3. 否定结构中 don’t have to 表示“不必” mustn’t 表示“禁止” You don’t have to tell him about it. 　 你没必要把此事告诉他。 You mustn’t tell him about it. 　　　　 你一定不要把这件事告诉他。

should 和 ought to  都为“应该”的意思，可用于各种人称。

ought to 着重表示客观要求，含有法律 上或道义上的责任。 should 往往表示说话者的主观意见，表 示一种必要性。—Ought he to go?—Yes. I think he ought to.

表示要求，命令时，语气强弱 :

should < had better < must

should 和 ought to  都为“应该”的意思，可用于各种人称。

ought to 着重表示客观要求，含有法律 上或道义上的责任。 should 往往表示说话者的主观意见，表 示一种必要性。—Ought he to go?—Yes. I think he ought to.

表示要求，命令时，语气强弱 :

should < had better < must

would 和 used to

1 ） used to 表示过去与现在或过去某时与后来的情况有不同，而 would 只表过去的情况。People used to think that the earth was flat.

She would go out for a walk in the morning when she was in the country.

2 ） used to 可表示过去习惯性的动作和经常的状态， would 只表示过去习惯的动作。He used to / would smoke while writing. 

She used to be fat. 

need 和 dare need 和 dare

•作为情态动词时，两者都主要用于疑问句、否定句和条件句。 •need 作实义动词时后面的不定式必须带 to ，而 dare 作实义动词用时 , 后面的to 时常可以被省略。•need, want, require, worth （形容词）后面接 doing 可以表示被动：need doing = need to be done

•作为情态动词时，两者都主要用于疑问句、否定句和条件句。 •need 作实义动词时后面的不定式必须带 to ，而 dare 作实义动词用时 , 后面的to 时常可以被省略。•need, want, require, worth （形容词）后面接 doing 可以表示被动：need doing = need to be done

Practice Practice 历年高考题历年高考题1. -- Mum, I’ve been studying English since 8 o’clock.

___ I go out and play with Tom for a while?

-- No, I’m afraid not. Besides, it’s raining outside now.

A. Can’t B. Wouldn’t

C. May not D. Won’t

2. I ____ pay Tracy a visit, but I’m not sure whether I will have time this Sunday.

A. should B. might

C. would D. could

3. Children under 12 years of age in that country ____ be

under adult supervision when in a public library.

A. must B. may C. can D. need

4. You ____ be tired – you’ve only been working for an

hour.

A. must not B. won’t C. can’t D. may not

5. You might just well tell the manufacturer that male

customers _____ not like the design of the furniture.

A. must B. shall C. may D. need

6. A left-luggage office is a place where bags _____ be left

for a short time, especially at a railway station.

A. should B. can C. must D.

will

7. -- Excuse me, but I want to use your computer to type a

report.

-- You ____ have my computer if you don’t take care of

it.

A. shan’t B. might not

C. needn’t D. shouldn’t

8. Hundreds of jobs ____ if the factory closes.

A. lose     B. will be lost    

C. are lost     D. will lose

9. Rainforests ____ and burned at such a speed that they will disappear from the earth in the near future.A. cut       B. are cut      

C. are being cut       D. had been cut

10. The first use of atomic weapons was in 1945, and their power _____ increased enormously ever since.

A. is B. was C. has been D. had been