昆明机床私募传闻2017:【英语语法】can和be able to的区别?

来源:百度文库 编辑:杭州交通信息网 时间:2024/05/01 03:55:04
老师说can是在一定状况下用的
be able to是表示能力问题
但是我又在电视上听有”You can't sing."翻译成”你不懂得唱歌.”
请告诉我他们的用法
最好举例句!

  1.  be able to 强调通过努力而获得的能力,而can则强调自身已具有的能力。如:

    She can sing the song in English. 她能用英语唱这首歌。

    He will be able to sing this song in English in a few minutes, too. 几小时之后,他也能用英语唱这首歌。

  2. be able to 强调一种结果,而can只强调一种可能。如:

    Luckily, he was able to escape from the big fire in the end. 幸运的是,他终于逃出了大火。

    If he got here a few hours earlier, I could save him. 要是他早几小时来,我还能救他。

  3. be able to 可以有各种时态;而can只有一般现在和一般过去两种时态。如:

    I could help you last night, but you didn’t come. 昨天晚上我能帮你,而你又没来。

    Can you see it there? 你能看见它在那儿吗?

    He is / was / will be able to help you. 

  4. can可用于表示可能性,推测,允许等情况,而be able to通常不这样用。

can 和be able to 的区别不大
can表示能力的意思 比如can you swim?(这时用be able to 就不妥)
也表示可能性 difficulties can be overcome
can也有请求的意思 can you give me a paper?

be able to 侧重是否有这个能力做某事 (比can更能体味出能力在句中的分量)一般可以和can互换
eg: he is able to leave

be able to & can都有表示能力,能做
他们的区别莫过于有无时态的变化 can是情态动词吧,所以没有;
be able to 的be 可以被切换成is are was 等等,这应该知道
而且好象be able to 有“能做”而且“做到了”的意思,can就不一定
You can't sing= you are not able to sing.

比较can 和be able to

1)can could 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. 他很快就能告诉你消息了。

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. 用于句首表示条件。
e. 表示成功地做了某事时,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)。
--- Could I have the television on?
--- Yes, you can. / No, you can't.

2)在否定,疑问句中表示推测或怀疑。
He couldn't be a bad man.
他不大可能是坏人。

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?

这是表猜测的用法,答案应该选D。否定的猜测,表示“肯定没有做某事”用can't。肯定的猜测,表示“一定做了某事”用must 。must have done表示过去肯定做了某事。must+动词原形,现在肯定怎么样。同理can't have done 表示过去肯定没做过某事,can't+动词原形,现在肯定没有怎么样。

此句的翻译:亨利现在肯定不在家,因为他刚刚从农场给我打过电话。

1.can用来表示现在的能力,be able to可表示将来的能力:
He can speak English.
After finishing his courses,he will be able to speak English.
2.can只能用于现在时,be able to 还可用于完成时,将来时:
Sorry,I haven't been able to answer your letter.

比较can 和be able to

1)can could 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. 他很快就能告诉你消息了。

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. 用于句首表示条件。
e. 表示成功地做了某事时,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)。
--- Could I have the television on?
--- Yes, you can. / No, you can't.

2)在否定,疑问句中表示推测或怀疑。
He couldn't be a bad man.
他不大可能是坏人。
be able to. 能, 会

At the weekends, I’ll be able to dress more casually. 在周末,我将穿得更加随便.

(1) casually 副词, 此处表示 “不经意地,随便地”

casually adj. 可以用来表示 “非正式的,不拘礼节的” casual clothes,便装

I’m used to dressing casually. 我习惯穿便装.

(2) able 形容词, “有能力的,能干的”

be able to 与can.

Can 表示 “能力,能够”时,只有现在时和过去时,can 和be able to 不能连用. Be able to 有现在时,过去时,将来时和完成时等多种时态.

He is an able man than I thought.他这个有比我想象的还要能干.
Will you be able to come to me tomorrow?明天你能来这里吗?
I have been able to swim.我已经会游泳了.

比较can 和be able to

1)can could 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. 他很快就能告诉你消息了。

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. 用于句首表示条件。
e. 表示成功地做了某事时,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)。
--- Could I have the television on?
--- Yes, you can. / No, you can't.

2)在否定,疑问句中表示推测或怀疑。
He couldn't be a bad man.
他不大可能是坏人。

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?

这是表猜测的用法,答案应该选D。否定的猜测,表示“肯定没有做某事”用can't。肯定的猜测,表示“一定做了某事”用must 。must have done表示过去肯定做了某事。must+动词原形,现在肯定怎么样。同理can't have done 表示过去肯定没做过某事,can't+动词原形,现在肯定没有怎么样。

此句的翻译:亨利现在肯定不在家,因为他刚刚从农场给我打过电话。