She didn't understand what was happening to her.

她并不知道发生在她身上的事。

I understand he will accept.

我听说他将接受。

I understand that they are almost destitute.

我听说他们几乎贫无立锥之地。

to understand the proof of a theorem

了解一项定理的证明。

He does not understand what you say.

他不明白你说什么。

The verb may be expressed or understood.

这个动词可明示亦可默喻；此动词可表出亦可省去。

to understand the folly of resisting

深知反抗之不智。

I understood him to say that.

我相信他说了那种话。

You don't understand.

你并不了解。