can和beableto的用法区别

can和beableto的用法区别

一、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，强调现在的能力，如：

be able to:

My sister is able to run a marathon.我妹妹能跑马拉松。

We will be able to attend the class next semester.下学期我们可以去上课了。

can:She can play tennis.她会打网球。

They could speak English at a very young age.他们很小的时候就能说英语。

Peter can type 100 words per minute.彼得每分钟能打100个字。

二、在过去时中，be able to 强调一种结果，而 can 只强调一种可能。如：

be able to:Luckily, he was able to escape from the big fire in

the end. ---->已经逃出了幸运的是，他终于逃出了大火。

The students were able to get an A on the test.---->已经学生们考试得了A。

can: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。

三、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：

can 现在时：Can you see it there? 你能看见它在那儿吗？

can 过去式：I could help you last night, but you didn’t

come. 昨天晚上我能帮你，而你又没来。

四、can可用于表示可能性，推测，请求，许可等情况，而 be

able to通常不这样用。

can 表示可能性：He can be at home now. 他现在可能在家。

can 表示推测：

The price is too high. That can’t be right. 价格太高。那价格不可能是对的。

can 表请求：Can I help you? 我能帮助你吗？

Can I read your newspaper?

我可以看一下你的报纸吗？

can 表许可：You can take the car, if you want.

如果想用那辆车，你就尽管用吧。

We can't wear jeans at work.我们工作时不准穿牛仔裤。