所…的grammar point · tier 1 · nominalizing 所 V 的: the thing that is V-ed
所 in front of a transitive verb turns the action into its object — the thing V acts on — and 的 hands that thing to a noun or stands in for it.
字源 FORM what the parts do
所 carries no meaning of its own — 戶 lent it the sound (hù worn down to suǒ), and the axe 斤 inside it belongs to the old felling-word, long borrowed away. 的 is the linker that fastens what precedes it to a noun. 所 opens ahead of the verb and 的 seals behind it; the verb caged between them turns into the thing the action lands on.
故事 STORY a scene to remember it by
所 steps in front of a reaching hand and freezes it; what the hand was reaching for is left sitting there, and 的 ties a label to it.
字源自撰記憶法
框 · Frame
[agent] 所 [transitive V] 的 (+ N) — the N that [agent] V-s
觸 · Trigger
Name the thing a verb lands on as a noun phrase: what is seen, said, known, focused on.
序 · The move
1Take a transitive verb and the agent doing it; put 所 before the verb.Is the verb transitive and its object the thing you want to name? 所 only nominalizes the object slot.
2Close with 的; either name the head noun after it or let 的 stand alone for the thing.Does 的 hand the verb-phrase to a noun (所看的書) or carry the noun itself (所看的)?
3Read it back as 'the [N] that [agent] V-s'.Is the head noun the OBJECT of the verb, not the agent? 所 picks the patient, never the doer.
例 · Examples
1一般來說generally speaking，語言學家linguists所關注的that which (they) focus on — the thing focused on是is語言規則the rules of language的問題the question of。
Generally speaking, what linguists focus on is the question of the rules of language.
Plain 看的書 already says 'the book read'; 所 adds no meaning, only a formal written register and a guarantee the head noun is the verb's OBJECT. 所看的書 = the book that is read, never the reader.
是…的 spotlights one circumstance of a settled event (when/where/how it happened). 所…的 names the patient of a verb as a noun. The official sentence stacks both: 所關注的 is the noun, 是 frames it.
✗ 語言學家所關注 → ✓ 語言學家所關注的 — 所 opens the nominalizer; 的 must close it.
✗ 所跑的人 (meaning the person who runs) → ✓ 跑的人 — 所 marks the object slot, so 所 cannot name the agent of an intransitive verb.
✗ 我所喜歡 → ✓ 我所喜歡的 — without 的 the phrase has no noun to land on.
English 'that which / what' is one word doing both jobs; here the work is split across two marks, 所 opening and 的 closing, with the verb caged between them.