Jack—I have good news for you!Rose—What?Jack—The educational department has carried out rules to reduce students' too much study load. Rose—Really? If so, I don’t have to stay up late to do so much homework and my mom may allow me to play computer games.Jack—The best thing I think is that I can have more spare time to take exercise after class.Rose—Sure. By the way, who is your favorite sports star?Jack—Liu Xiang, I should say.Rose—Tell me something about him.Jack—Well, maybe I can show you some photos.

We use modal verbs to talk We use modal verbs to talk about:about:•Ability （能力）•Obligation （义务）•Certainty （可能性）•Permission （允许）

We also use modal verbs We also use modal verbs to:to:

•Make requests （提出请求）•Make suggestions （提出建

议）•Make offers （提供帮助）•Give advice （提出意见）

1.Ability ( 能力 ):

Liu Xiang can run the 110m hurdle race within 13 seconds.

can/could:1. can 一般表示与生俱来的能力或者一种客观可能性 , 还可以表示请求和允许 。

Learning English_____ be difficult.can

Man can not live without air.

can/could:

2. 在疑问句中，用 could 可表示请求，语气较委婉。

— ____ you lend me some money?— Sure.

Could

He asks if he ____ smoke here.could

can/could:3. 表示惊异、怀疑、不相信的态度。（主要用在否定句、疑问句或惊叹句中）

He’s such a nice person that he ______ commit the crime.

can’t

你怎么会如此地粗心！ How can you be so careless!

Can this be true?

can/could:4. can never/can’t……too 表示

“无论怎样…也不过分”，“越…越好” 。你过马路的时候再小心也不为过。

You can’t be too careful while crossing

the road.

can/be able to 区别 :Edison always wondered why h

ens could hatch ( 孵 ) chickens while he was not able to.

Question: Are the two modal verbs interchangeable ( 互换 ) ? If not, why?

can 表示与生俱来的能力与生俱来的能力或一种客观可能一种客观可能，而be able to 更加强调通过后天的学习和努力通过后天的学习和努力获得的能力，获得的能力，或者在某个客观的场合和背景下在某个客观的场合和背景下，能做到的事情。

can/be able to 区别 :1.A big fire broke out in

ABC hotel yesterday. Luckily, everyone __________ run out of the building.

was able to

2. If you feel like it, you ___ go for a walk in the park.

can

I’m so tired! I have to do the training for at least 10 hours

a day!

2.Obligation ( 义务 ):

…yet, He must work hard to win the gold medal.

Although Liu Xiang is so gifted in hurdle race…

advisability

necessity

ought to/should

have to

must

You mother brings you up and takes good care of you, so when she is old, you ___ look after her in return. A.can B.may C.have to D.must

Shi Dongpeng might win a medal at the Olympic games.

Although the chance

of winning a medal is

small, I’ll try my best!

3.Certainty ( 可能性 ) :

very uncertain

almost certain

might

should mustmay could ought to

will

1.He _____ be at home.

2.He _____ be at home, for he just called me from his home 15 seconds ago.

A.may B.might C.must

A.may B.might C.must

—They___ be doing the experiment in the lab.—Why ？—Because the lights are still burning.

A.could B.can C.must D.would

4.Permission ( 允许 ):

May I eat KFC if a win the gold medal?

may/might:1. 表示许可。表示请求、允许时，

might 比 may 的语气更委婉一些。— Might/May I use your computer? — Yes, you can./No, you can’t.

may/might:2. 用于祈使句中表示祝愿。

3. 表示推测、可能（只用于肯定句，疑问句则要用 can 或 could ）。

祝你成功！ May you succeed.

He may be very busy now.

May you be happy all your life.

5.Making requests ( 提出要求 ):

Can you help me with my training?

I don’t know how to use

this equipment!

6.Making suggestions ( 提出建议 ):

Shall we do the training in the morning?

It’s too hot to take

exercise in the

afternoon.

shall: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、向对方请示或提供帮助 。

1.Shall we begin our lesson?

2.When shall he be allowed to leave hospital?

3.Shall I carry this bag for you?

shall: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。

You shall fail if you don‘t work harder.

He shall be punished.

等我读完这本书，就会给他的。 He shall have the book when I finish it.

警告威胁

允诺

7.Making offers ( 提供帮助 ):

Don’t worry, dear, I will wash them right away.

Mom, my dirty

clothes have been piled up! I don’t have

time……

will/would:1. 表示请求、建议等， would 比 wil

l 委婉客气。

sentence pattern

Would you please…

Would you mind…Would rather…

Would you like…

will/would:

2. 表示意志、愿望和决心。

I will never do that again.

will/would:3. 可表示经常性、习惯性、倾向性。翻译为“经常、惯于、总是”。1.The old man would have a smoke under a big tree every afternoon after he finished his farm work.

2. 门就是打不开 !

The door won’t open.

will/would:

I will go to the park with you tomorrow if you will offer me lunch.

Question: Is this sentence correct? Why?

情态动词

助动词

8.Giving advice ( 提出意见 ):

You should not/ought not to eat so much before running.

How delicious!!!

should:

1.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 。Should I open the window?

你应该马上去教室。 You should go to class right now.

should:

2. 情态动词 should 用于第一人称时可以表示说话人的一种谦逊、客气、委婉的语气。

Rose—Sure. By the way, who is your idol?Jack—Liu Xiang, I should say.I should advise you not to do that again.

…After showing Liu Xiang’s photo album, Jack is going to write an article for the school magazine about how cities are chosen to host the Olympic Games. However, Jack has some difficulty in choosing the correct modal verbs.

Please help Jack finish this article. Before you do it, you should pay attention to a checklist showing what is important for a potential (潜在的 ) Olympic city.

When choosing a city to host the Olympics, there are certain things we need to consider. The first is the sports facilities. The city ___ (must, should) have an Olympic stadium and also ___ (has to, ought to) provide first-class training grounds. The chosen city ___ (must, should) also have plenty of good hotels and ___ (could, must) have an international airport nearby.

must

has to

must mus

t

The city itself _____ (must, should) be clean and public transport _______ (has to, ought to) be convenient. If there were lots of good restaurants in the city, this would make it more attractive.

should

ought to

Another thing we should think about is the people who live in the city: if a lot of people ____ (could, might) speak English, it would be very helpful for tourists. Visitors ____ (have to, may) be interested in tourist attractions too, so we also need to pay attention to the standards of services. Finally, we should consider green spaces. If a city has plenty of parks, this ____ (could, must) help its bid to be an Olympic city.

could

may

could

Jack wants to surf the internet after school…

Jack—Excuse me, _____ (may/must) I use your computer for a while”

Rose—Yes, you _____ (should/can). But it is not connected to the Internet, so if you want to check your e-mail, you won’t be able to.

Jack—Then, I will ______ (can/have to) find another one, but thank you anyway.

may

can

have to

Jack is having a conversation with his mom…Mom—If you _____(can/must) finish your homework today all by yourself, you _____(shall/must) go to the cinema with your classmate tomorrow.

Jack—I always finish my homework on time, but every time you break your promise.

Mom—But this time will be different, I promise.

Jack—Ok. I _____(will/need) try my best. If it is not so difficult, it _____(can/must) be finished before 10 pm. I just hope you will keep your promise.

can

shall

willcan

We mustn’t play with scissors. You may get hurt.

Look at the following pictures, discuss with your partner and then

use one or two sentences with modal

verbs to tell us the information you can get.

We mustn’t stand under the tall tree when there is thunder and lightening.

Although animals are our best friends, we shouldn’t get too close with them. Sometimes they may spread disease.

We shouldn’t play tricks on our classmates in class.

Question: How can we deal with exercises concerning modal verbs?Functions & usage of modal verbs

Language context (上下文、语境 )