be able to和can的区别

Question

如题所述

Answer 1

be able to和can的意思都是“ 能，能够”，一般情况下可以互换，但can 只有两种时态，即一般现在时can 和一般过去时could； 而be able to 可用于各种时态。

如
1 . He can swim .
= He is able to swim .
他会游泳。

2. She could write when she was three years old .
= She was able to write when she was three years old.
当她3岁时她会写字。

3 . He will be able to finish the work in two minutes.
两分钟后他能完成这项工作。

Answer 2

can 与 be able to 用法比较
在一般现在时主动语态中表示“能”、“会”时,两者可互换,意义差别不大.如：
I can / am able to reach the apples.
但在以下几种情况中两者不能换用：
1、在词义上,can 除可以表示“能”、“会”外,还可以表示“许可”、“允许”或可能性,而 be able to 则不可.例句：
A :Can it be true?
B :No,it can't be true.
2、当表达将来的能力时,一般要用 will be able to； can 一般只有现在时和过去时两种时态形式.用于完成时等其它时态时,也用 be able to.例句：
1) I'll be able to speak English in another few months.
2) If I have a good sleep,I'll be able to work out the problem.
3) I've not been able to find my bike.
但是当人们现在决定将来是否有做某事的能力时,can 也是可以用的.例句：
I'm too busy today,but I can help you with your English tomorrow.
3、be able to 多表示“人”有能力或技巧做某事,一般不用于指物；而 can 表示人、物的“能”、“会”都可以.例句：
This kind of car can run very fast.It's new.
4、can 可以有被动语态形式,而 be able to 则不能用于被动语态.例句：
The mistake can't be corrected.
5、can 与 be able to 不能重叠使用.例句：
（误）He can be able to do it well.本回答被提问者和网友采纳