I don't pretend (that) I know much about the subject, but...

我不敢说自己对这个主题有多了解，但是…

《牛津词典》

I don't know much about it, so I don't feel qualified to comment.

关于此事我所知不多，所以觉得没资格评论。

《牛津词典》

We don't know much about it.

我们对此了解不多。

youdao

why,when we do not sleep, we do not function well. We just do not know much about sleep at all."

VOA: special.2009.08.26

Actually, this is my first Earth Day and I don't know that much about it.

实际上这是我过的第一个地球日，我并不是很了解。

关于世界地球日 - SpeakingMax英语口语达人

These are very interesting results, but sort of the bias that everything should be done with white males that existed for many years hid some of these really interesting and important interactions that otherwise people didn't know much about.

这都是些值得关注的结果,但多年来对白人男性的研究带来的偏见,掩盖了这些有趣而重要的相互关系,人们对此知道得不多

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

He didn't know much about entertainment or the fountain drink biz, but he knew Arnold.

FORBES: Pop Music

"I don't know much about art, really, but I am moved by beauty, " he says.

BBC: Brazil's Inhotim park celebrates giant art amid nature

He said he did not know much about the donor but was "humbled by their gift".

BBC: Brendan Marrocco, US quadruple amputee, gets new arms