当我告诉你，我多年来都不知道什么是真正的快乐时，我知道你相信我。

I am sure you believe me when I tell you that I have not known any real joy for years.

youdao

如果你不知道什么是鹰头狮，请看图片。

If you don't know what a Gryphon is, look at the picture.

youdao

我们知道什么和不知道什么这个问题一直困扰着我。

The question of what we know and do not know constantly bothered me.

youdao

Now,the problem with this is that Papias and these other people didn't really know what they were talking about.

问题是帕皮亚和其他人,根本不知道自己在说什么。

耶鲁公开课 - 新约课程节选

I chose English Literature because when I started off a university, I didn't know what it was I wanted to do.

我选英语文学是因为当我刚上大学的时候，我不知道自己到底想做什么。

为何选那门专业？ - SpeakingMax英语口语达人

We've had a great deal to do with it, but of course we still haven't the slightest idea what it is.

我们花了很大的功夫来接解决这个问题，但我们仍然一点都不知道语言是什么。

耶鲁公开课 - 文学理论导论课程节选