對（於）…而言grammar point · tier 2 · from X's standpoint 對（於）…而言 (for X / as far as X is concerned, formal)
Frames a perspective-holder, then states how something weighs or appears from their standpoint, in a formal register.
字源 FORM what the parts do
Two brackets close round one party. 對 opens it: a hand (寸) raises the notched tablet (丵) and turns to face the one across; 於 may follow to mark the party as the thing faced. 而言 closes it: 而 is the beard-graph on loan as a joining word, and 言 is a mouth (口) with the breath rising above in straight strokes, the words said out. Read together as "and so, spoken-of." The party whose side you take sits between.
故事 STORY a scene to remember it by
Someone turns and faces one person at the table, then keeps still. From that one's place the same matter sits at its own weight, and what is said next reports only that weight.
字源自撰記憶法
框 · Frame
對（於） [perspective-holder] 而言，[comment from that standpoint]
觸 · Trigger
You want to seat a judgment in one party's vantage in formal or written register — say how a thing weighs or appears for them, not aim an action at them.
序 · The move
1Open with 對, optionally 對於, and name the party whose vantage you take.Is the slot after 對（於） the one whose viewpoint frames the comment, not a target the verb acts on?
2Close the bracket with 而言 and a pause, then state the comment.Could the comment stand alone, with 對（於）…而言 only seating the viewpoint?
3Read it back from the picture.Does it report how the thing weighs from their place (success), rather than send an action at the person (failure)?
例 · Examples
1對於公司的員工staff, employee而言，加薪a pay raise是一種很大的鼓勵a great kind of encouragement。
For the company's employees, a raise is a great encouragement.
界 · Boundary
對…來說
Both seat one party's standpoint and report how a thing weighs from it. 對…來說 is the everyday closing; 對（於）…而言 is the formal, written closing. Same move, plain register against formal register.
Directional 對 aims an action at the person faced (對我笑 = smile at me). 對（於）…而言 seats a judgment in their viewpoint and lands no action on them (對我而言 = as far as I am concerned). Action-recipient against viewpoint-seat.
至於 switches the topic to a new item (至於錢，再說 = as for the money, later). 對（於）…而言 holds one party's standpoint and reports how things weigh from it. Topic-switch against standpoint-anchor.
✗ 對我而言笑 → ✓ 對我笑 (an action aimed at a person drops 而言; 對（於）…而言 frames a viewpoint, not a target)
✗ 而言對學生這很難 → ✓ 對學生而言，這很難 (對 opens, the party sits between, 而言 closes — the brackets do not swap)
✗ 對我而言，你笑了一下 (a one-off action narrated under the frame) → ✓ 對我而言，這件事很重要 (the frame reports a standing judgment from the seat, not a single event aimed outward)
English 'for X' covers both 'X is affected' and 'from X's point of view'. 對（於）…而言 is only the second, in formal register; the affected-party 'for' often wants bare 對 or 給 instead.