高中英语必修三情态动词语法

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高中英语必修三

情态动词（ unit 1 ，unit 2）

一、情态动词的特点:

1.没有人称和数的变化。

2. 有些情态动词有过去式的变化:

. will → would , can → could , may→ might ,dare → dared

二、情态动词的否定式:

情态动词+ not +动词原形can not: can't , must not: mustn't , need not : needn't …

三、情态动词的用法及相互区别, 是考试的内容之一

1. can , be able to be able to 表示经过努力后, 能够做到; be able to 有多种形式的变化。

can

1). 表示体力或脑力方面的能力;

2). 表示允许、可能性。

could 是can的过去式, 表示过去有能力及过去存在的可能性 ; 用于疑问句表示委婉地提出问题。

1) The fire spread through the hotel very quickly but everyone ____ get out. (NMET 97 )

A. had to

B. would

C. could

D. was able to

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2) -Will you stay for lunch

-Sorry, __. My brother is coming to see me. (NMET99)

A. I mustn't

B. I can't

C. I needn't

D. I won't

表示询问或说明一件事可不可做; 表示某事有可能发生。might是may的过去式; 用在疑问中比may委婉、客气。

1) -May I take this book out of the reading-room

-No, you mustn't. ( Yes, you may.)

2) -Might I make a suggestion -Yes, you may.

3. must

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1). 表示必须要做的事: 必须

2) 表示很有把握的推断: 一定, 准是。have (has)to : have (has)got to 必须, 不得不。过去式: had to

3) -Must I get to the station before three o'clock

-Yes, you must. ( No, you needn't. )

4) I'm afraid you will have to wait a while.

5) She must be in the classroom now.

6) Mary ____ be in Paris, I saw her in town only a few minutes ago. (NMET 94)

A. mustn't

B. shouldn't

C. can't

D. may not

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4. shall

1) 在疑问句中, 用于第一、三人称表示说话人征求对方的意见或向对方请求。

2) 用于二、三人称,表示说话人给对方的命令、警告、允诺等概念。

1) - Shall I place an order with you now -No, you needn’t.

-Shall he turn down the radio a bit -

Yes, please.(No, please don't.)

2) You shall have the English book as soon as I finish it.

3) Everything that he owns shall be taken away from him.

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4) Your brother seldom comes to see you, ____

A. does he

B. doesn't he

C. will he

D. isn't he

5) It's a fine day. Let's go fishing, ____

A. won't we

B. will we

C. don't we

D. shall we

5. should 应该 ; 应当

1) You should listen to the doctor's advice.

2) You should study the article carefully.

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6. will, would

1) 在疑问句中用于第二人称,表示说话人向对方提出请求或询问。用would语气更加婉转。

2) will 表示现在的习惯性动作或状态; would 表示过去的习惯性动作或状态。

3) will 用于各种人称, 表示意志、意愿、决心、允诺; would 表示过去时间的意志、意愿、......。

(1) Don't smoke in the meeting room, ___ you

A. do you

B. will you

C. can you

D. could you

-Will you come with me -Yes, I will.(I am sorry , I can't.)

(2) -Would you tell us something about yourself -Yes, I will.

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(3) - It's my birthday tomorrow. Don't forget to come to my party.

- _____ .

A. I don't

B. I won't

C. I can't

D.

I haven'

7. ought to 应该; 应当

1) You oughtn't to smoke too much.

2) She ____ for what she has done.

A. ought to praise

B. ought be praised

C. ought to have praised

D. ought to be praise

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8. dare 1. dare to come 2. dare come

1) He dare not tell the truth.

2) He doesn't dare to come out at night.

3) I don't know whether he ____ try.

A. dare

B. needs

C. wants

D. is allowed