could not have done是什么意思?

could not have done是什么意思?

could not have done是什么意思?

1、本不能做某事却做了

2、不可能做某事

是上面哪一个?还是两个都是?还是都不是?

两个都是,但常表示“本不能做某事却做了”.

表示“不可能做某事”是对过去事情的推测.

eg：He couldn't have failed the exxam,and he studied hard recently.

看例句就知道了

1.

She could not have done it.

她不可能做了这件事。

2.

Without your help , we could not have done the work well .

如果没有你的帮助，我们不可能把工作做好。

3.

Had it not been for your ...

应该是“不可能做过”