情态动词（I )

Question：动词前面经常会见到can,must 等，我想了解这方面的知识。

Answer：好的，今天我们就开始来学习情态动词。

情态动词（I )

Can , could , be able to

Reading:

Jane Smith is studying languages in London. She’s having an interview for a job as a tourist guide.

A: Miss Smith, how many languages can you speak ?

B: I can speak Spain, Italian and German. I’d like to be able to speak a bit of Japanese, but they don’t teach it at my college.

A: It’s a pity, because we get a lot of Japanese visitors in London. We need people who can speak Japanese, but we haven’t been able to find any. But this summer there’ll be a lot of German and Spanish visitors too, so you’ll be able to use your Spanish and German. Can you start work in May ?

B: No, I’m afraid I can’t . I can’t miss college. I won’t be able to start until the end of term in June.

I．Can和be able to

1． can/can’t(=cannot)+不带to的不定式可以表示某人能或不能做某事。

I can speak Spanish. (=I know how to speak Spanish.)

I can’t speak Japanese. (= I don’t have the ability to speak Japanese.)

2． can/can’t(=cannot) +不带to的不定式还可以表示可能或不可能。

Can you start work in May ? (=Is it possible for you to start in May ?)

I can’t miss college. (=It isn’t possible for me to miss college.)

3．can和 can’t 没有人称和数的变化 ( I can, he can, we can等)

4．表示现在用 be able to或can都行，但是be able to 更正规，显得不平常。

 How many languages can you speak ?

(How many languages are you able to speak ?则很正规。)

5．因为can没有不定式和完成式等，下列句式中要用be able to： 

I’d like to be able to speak a bit of Japanese. (不定式)

We haven’t been able to find any.（现在完成式）

6．表将来时通常可用can或will/won’t be able to，但强调将来时间时则用will/won’t be able to

Can you start work in May ?(或 Will you be able to start work in May ?0

I won’t be able to start until June.(或 I can’t start until June.)

You’ll be able to use your Spanish and German.

小练习I： 改写句子，使之和原句同义： 

1.Is Jane able to speak Japanese ?   _____ Jane speak Japanese ?

2.She isn’t able to start work immediately.  She ____ immediately.

3.She can’t start work in May.  She _____.

4.She can start work at the end of term. She ____.

II．Could 还是was/were able to ？

Reading：

Jane finished college on June 13^th and she was  able to start work the next day. She took a group of Germans round London. Most of them could speak English. At London Zoo one woman dropped her camera into the lion’s enclosure. She could see the camera, but she couldn’t reach it. Fortunately a keeper was able to reach it with a fishing net. Later ,Jane’s group was in St Paul’s Cathedral. One man started to play the organ. He could play very well. Jane told him that visitors couldn’t play the organ, but he couldn’t persuade him to stop. Later, in a big department store in Oxford Street, two members of Jane’s group got sick in the lift. They couldn’t get out because they weren’t able to open the doors. After about 30 minutes workmen managed to open them and the two Germans were able to get out.

1． could 或was/were able to用来表示过去：

2．表示一般能力时，could 比was/were able to更常用：

Most of them could speak English.(比were able to speak English更通俗)

3．但是，在肯定句中表示过去的一个特殊的行为或情况时用was/were/able to，而不用could。

Jane finished college on Jane 13^th and she was able to start work the next day (不说could start)

The two Germans were able to get out (不说could get out)

(They got out of the lift 这是一个特殊行为)

4．否定句中既可以用couldn’t也可以用wasn’t/weren’t able to，不过couldn’t更常用。

She couldn’t stop the man from playing the organ.

(或She wasn’t able to stop the man.)

5． 有时couldn’t有wasn’t/weren’t allowed to的意思：

She explained to him that visitors couldn’t play the organ.

(=visitors weren’t allowed to play the organ.)

6．在感官动词see, hear, feel等，和如understand这类动词前，通常用could而不用was/were able to：

She could see the camera, but she couldn’t reach it.

小练习II.：用could/couldn’t  was/wasn’t/were able to填空：

1. One of Jane’s group ____ play the organ very well.

2. The woman who dropped the camera ____ reach it herself.

3. But the keeper ___ reach it with a fishing net.

4. At last ,after 30 minutes, the workmen ____ open the lift doors.

上期答案 ：

I．1 They will be arriving.

2  Yes, they will.

II.1 She’ll have finished her work.

 2 Her uncle will have arrived.

III.．1 She won’t be in bed./She’ll have got up by now.

2 She’ll be doing the shopping.