V於grammar point · tier 1 · V於 — pin a verb to its point (graduate from / locate at / arise in)
· yú
Suffixes 於 onto a verb to fasten the action to the point it turns on — the place it lands at, the source it issues from, the time or domain it sits in.
字源 FORM what the parts do
於 is a worn crow-graph, the same bird as 烏, hired out as the empty joint of the sentence, at, in, to. Hung straight off a verb it carries no meaning of its own; it only fastens the action to the point named after it.
故事 STORY a scene to remember it by
A verb swings forward and 於 drives the peg in behind it, pinning the action to the point it names.
字源記憶法
框 · Frame
[subj] [verb] 於 [anchor point (place / source / domain)]
觸 · Trigger
You have a verb and the one point it turns on — where it lands, springs from, or sits — and you want them fastened together in formal or written register.
序 · The move
1Set the verb, then hang 於 straight off its tail.Does 於 sit AFTER the verb? Before it, 於 marks nothing — this slot is a verb-suffix.
2Name the point after 於 — the place, source, time, or domain the action turns on.Is this the single point the verb anchors to, not the agent doing it?
3Keep the register formal or written.Would speech split this into a coverb before the verb (在/從…+V)? If so, this V於 is the written compression.
例 · Examples
1李明華畢業graduate於yú — at/from (pins the verb to its source point)中文系the Chinese department (the source graduated from)。
在 + place sits BEFORE the verb and frames where the action happens (在中文系畢業 — graduate while at the dept). V於 hangs AFTER the verb and pins it to the point it issues from or lands on (畢業於中文系 — graduate out of the dept). Front-frame vs tail-peg.
從 + source is the spoken coverb before the verb, tracing motion out of a starting point (從中文系畢業). V於 is the written tail-suffix doing the same fastening in one compressed joint; 從 cannot follow the verb, 於 cannot precede it.
於中文系畢業 ✗ → 畢業於中文系 ✓ (於 is a verb-suffix; it follows the verb, it does not head the clause)
他畢業了於中文系 ✗ → 他畢業於中文系 ✓ (nothing wedges between the verb and 於; the peg is driven straight off the verb's tail)
我把信寄於他 ✗ → 我把信寄給他 ✓ (a human recipient takes 給, not 於; 於 pins to a place/source/domain, not a person handed the goods)
English 'graduate from / located at / based in' uses a free preposition that can sit anywhere; learners reach for a word before the verb. 於 only ever follows the verb, as one fused joint, and only in formal or written register.