我不理解他的意思。用英语怎么说？

我不理解他的意思。

I did not comprehend his meaning.

did

v. 做( do的过去式)，干，学习，研究；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

not

adv. 不，[用以表示否定、否认、拒绝、禁止等]不是，几乎不，未必，没有[用于否定后面的词或短语]；

例句
It became very clear that the incident was not just an aberration, it was not just a single incident.
事实已经很清楚，这件事不是偶发的，它并不是一起孤立的事件。

comprehend

vt. 理解，领会，包含；

例句
I just cannot comprehend your attitude...
我就是无法理解你的态度。

his

pron. (he的所有格)他的，(he的物主代词)他的东西；det. 属于他的，用于名词前，自己的，指某人的，上帝的；

例句
He claimed that his parents had abandoned him...
他声称父母遗弃了他。

meaning

n. 意思，意义，含义，意图；adj. 有意思的，意味深长的；vt. 意味(mean的现在分词)，意思是；

例句
The term Wissenschaft has a much broader meaning than the English word 'science'.
Wissenschaft这个术语比英语词science含义更广。