我不明白她想要什么。

I can't make out what she wants.

《牛津词典》

我不明白你在说什么。

I don't understand what you are talking about.

《柯林斯英汉双解大词典》

我不明白他在说些什么。

I don't understand what he's saying.

《牛津词典》

In one Psalm--it's great--he's one of the gods and he says, "You know, you guys don't know what you're doing. Let me take over."

其中一篇写得很好，上帝是众神的一员，他说道，“知道吗，你们根本不明白自己在做什么，还是让我来吧“

耶鲁公开课 - 旧约导论课程节选

I'm not sure what she said.

我不明白她说什么。

I'm sure 实战 - SpeakingMax英语口语达人

I don't understand what your metaphors are all about.

我不明白你暗喻的是什么。

耶鲁公开课 - 文学理论导论课程节选