TSUMUGU · TBCL 1 (est.) · 語法
在
grammar point · tier 1 · locative 在 (be located at a place)
· zài
Locative: 在 + a place says someone or something is sited there.
Hook inherited from 在.
Locative
框 · Frame
[subj] 在 [place]
觸 · Trigger
You want to say where someone or something is.
序 · The move
1Name the subject, then 在.Is what follows 在 a place?
2Put the place straight after 在.A place noun follows, not a verb — so this reads as located, not ongoing.
3Stop; 在 already carries 'is at', so no extra verb of being.No 是 and no separate verb wedged in before the place.
例 · Examples
1他he在is at學校school。
He's at school.
界 · Boundary
progressive 在 (我在吃飯)What follows decides it: a place after 在 means located there (他在學校); a verb after 在 means the action is going on now (他在吃飯).
他是在學校。 → 他在學校。
他在。 → 他在學校。
他在學校在。 → 他在學校。
English 'at/in' is a preposition needing a separate verb ('he is at school'); Chinese 在 is itself the verb here, so no extra 是.