所 + verb (nominalizer)

Structure (Subject +) 所 + transitive verb

所 (suǒ) precedes a transitive verb and nominalizes it, turning it into "that which is [verb]ed": the focus falls on the OBJECT of the action. From this come very common set phrases in written and formal register: 据我所知 "as far as I know", 所见所闻 "what one sees and hears". It is the foundation of two other C1 structures: the literary relative 所…的 and the passive 为…所…. On its own, 所+verb sounds formal and orderly, typical of essays and the press.

Examples

据jù我wǒ所suǒ知zhī，会huì议yì已yǐ经jīng取qǔ消xiāo了le。
As far as I know, the meeting has already been cancelled.
这zhè次cì旅lǚ行xíng的de所suǒ见jiàn所suǒ闻wén让ràng我wǒ深shēn受shòu触chù动dòng。
What I saw and heard on this trip moved me deeply.
他tā所suǒ做zuò的de一yī切qiè都dōu是shì为wèi了le家jiā庭tíng。
Everything he does is for the sake of his family.
言yán行xíng不bù一yī，所suǒ言yán非fēi所suǒ行xíng。
His words and deeds don't match: what he says is not what he does.

Levels are indicative: they follow the standard Chinese Grammar Wiki (AllSet Learning) progression, not an official HSK 3.0 mapping. We never assign levels by eye.

This point and the other 370, with audio on every example, inside Wanyu.