所知道的

what (someone) knows

→ 所
phrase Rare #23,554
what (someone) knows The 的 phrase turns 知道 into a noun phrase, referring to what someone knows.
CH: 这就是我所知道的。
EN: This is what I know.

我所知道的就是她昨晚把我吵醒

All I know is that she woke me up last night.

— 歌剧红伶 (1981)

我已经告诉你我所知道的了

I've already told you everything I know.

— 我仍在此 (2024)

这是我们所知道的

This is what we know.

— 爱乐之城 (2016)

我所知道的是你才是内鬼

What I do know is that you’re the traitor.

— 落水狗 (1992)

你最好马上讲出所知道的一切

You’d better tell me everything you know right now.

— 大逃杀 (2000)