中考英语专题复习第11讲：情态动词.doc

、中考英语专题复习第11讲：情态动

词一、情态动词的类型和特征

1 .情态动词的类型

(1)只做情态动词的有：must, can(could), may(might)

(2)可做情态动词也可做实义动词的有：need

(3)可做情态动词也可做助动词的有：will(would); shall(should)

(4)具有情态动词某些特征的有：have to, ought to

2 .情态动词的特征

(1) 有一定的词义，但不能单独做谓语，必须和行为动词或系动词连用，构成谓语。

(2) 无人称和数的变化(have to除外，用于第三人称时用has to),如：He has to stay here.

(3) 后接动词原形。如：She may lost her way.

(4) 具有助动词的作用，可用来构成否定句、疑问句及用于简明回答，如：

Can she sing an English song?…Yes, she can.

二、情态动词的用法

1. can, could 的用法

(1) 表示能力，译为—会|| o 如：Can you play basketball?

(2) 表示怀疑、猜测，常用语否定句和疑问句当中。如：Li Hua can ' t be in the classroom.

(3) 表示请求或允许，多用于口语中，译为一5J以||,相当于may。如：You can go now.

(4) could 是can 的过去式，可以表示过去的能力。I could swim when I was seven years old.

2. may的用法

(1) 表示推测，译为一可能，也许||,用于肯定句中。如：He may come tomorrow.

(2) 表示请求、许可，译为一可以||。如：May I borrow your book?

can和may均可用来表示意见或允许，译为一可以|| , 一般可以互换使用。

注意：may表示请求时，用于主语为第一人称的一般疑问，其否定回答用mustn, , i不用may not,译为一不可以，不许，禁止 ||。如：…May I go now?…No, you mustn ' t.

(3) 表示祝愿。如：May you success!

3. must的用法

(1 )表亦一必须11 o

(2) 表示推测，一一定|

(3) must表示推测时，一般用于肯定句，在疑问句和否定句中一般用can,否定句中也可用may,但may not 表示一可能不||,而can' t表示一不可能II

(4) 否定句中mustn'表t示禁止，译为 T允许||。以must开头的一般疑问句，肯定句回答用must,而否定回答常用needn' t表示一不需要，不必||,相当于don' t have to。女口：

There' s someone knocking at the door. It must be Jim.

—Must I finish the project today?— No, you needn ' t.

4. need的用法

(1) 情态动词—wM 有必要|| —般用于否定句或疑问句中。

You needn't come here this afternoon.

(2) 行为动词F要，有必要||可以用于各种句式中。

You don't need to go now. I need to have a rest.Do we need to finish all the work today?

5. had better 的用法

一had better 动词原形 || 表示最好做某事，否定式用had better not。You' d better stay at home.

6. shall(should), will(would)的用法

(1) shall 用于第一人称表示征求意见、询问。Shall I open the window? Shall we have lunch here?

(2) should 常用来表示义务、责任。如: We should obey traffic laws.

(3) will用于第二人称表示询问、请求，也可用于表达现在的Fill。

Will you pass me the book? We will do anything for you.

(4) would用来表示过去的意愿或委婉询问。如：Would you tell me the way to the station?

would rather 与than 连用, 其结构是：would rather do sth than do sth 或would do sth rather than do sth。如果用的动词相同，贝9 than 后省去该动词。I would rather play football than baseball.

三、易混点点拨

l. can 和be able to

1) can表示能力；可能(过去时用could),只用于现在式和过去式(could)。be able to可以用于各种时态。

They will be able to tell you the news soon.

2) 只用be able to

a.位于助动词后。

b・情态动词后。

c. 表示过去某时刻动作时。

d. 表示成功做了某事只能用was/were able to不能用could.

He was able to flee Europe before the war broke out.= He managed to flee Europe before the war broke out.

注意：could不表示时态

1）提出委婉的请求，（注意在回答中不可用could）0

■.- Could I have the television on?— Yes, you can. I No, you can't.

2）在否定，疑问句中表示推测或怀疑。He couldnl be a bad man.

2. can '和may not

can'语t气肯定，表示一不可能II may not语气不肯定，表示一可能不||。

-Will they go for an outing today? -They because it seems that the weather is not so fine.

A. mustn't

B. can't

C. needn't

D. may not

3. must 和have to

must表示主观看法，意为一必须、应该|k have to强调客观需要，意为一不得不\\> 例：1).Look! The traffic light is red. I stop my car.

A. have to

B. ought

C. must have

D. must

2). It's still early. You.

A. mustn't hurry

B. wouldn't hurry

C. may not hurry

D. don't have to hurry

4. can'和t mustn' t

can,意t为一不可能||,表示推测。mustn' t意为一禁止、不许|| ,不表示推测。

例：1) Henry be at home because he phoned me from the farm just now

A.mustn't

B.isn't able to

C.may not

D.can't