It is difficult to understand what she has said

题目

It is difficult to understand what she has said
如果在understand 后是用what she was saying是否可以,如果不行,理由是什么?

答案

语法虽行,但意思有所不同：
It is difficult to understand what she has said.
很难理解她说的话的意思.
It is difficult to understand what she was saying.
很难领会她当时说的是什么.