只是grammar point · tier 1 · 只是 — only, just (attach one minor qualification)
Keep the prior claim standing, then attach the one minor thing that qualifies it without overturning it.
字源 FORM what the parts do
只 carries only — the graph is borrowed for that sense (a mouth 口 with the breath 八 drawn off below, an old final particle). 是 sets the thing down as so (the sun 日 over straight 正, what stands true). Side by side they keep the main claim and narrow the catch to one small thing set beside it, not against it.
故事 STORY a scene to remember it by
The main thing stands tall and unmoved, and 只是 sets one small qualification down beside its foot, too slight to topple it.
字源記憶法自撰
框 · Frame
[clause A holds]，只是 [one minor qualification on A]
觸 · Trigger
The main claim holds; now the single small reservation that does not undo it.
序 · The move
1State clause A as a claim that stands on its own.Does A still hold after the qualification, or does the qualification cancel it?
2Place 只是 at the head of clause B.Is B a single minor reservation, not a second equal point?
3Keep B slight — a partial exception, not a reversal.If B turns the whole expectation against A, reach for 但是 instead.
例 · Examples
1他he身體body, health很健康is very healthy，只是only, just眼睛eyes不太好not so good。
He is in good health; only his eyes aren't so good.
雖然…但是… flags a full reversal of the staged expectation; 只是 needs no opener and concedes only one small thing.
他很努力，只是失敗了。✗ → 他很努力，只是運氣不好。✓ (B must be a minor reservation, not a fact that overturns A; for a real reversal use 但是)
只是他眼睛不太好。✗ (an opener with no clause before it) → 他身體很健康，只是眼睛不太好。✓ (只是 needs clause A to qualify)
他身體很健康，只是很有錢。✓-grammar but ✗-sense → 他身體很健康，只是眼睛不太好。✓ (B should qualify A, not add an unrelated point)
English speakers map 只是 onto 'but', which signals a real contrast; 只是 is the softer 'only / it's just that', so using it where the second clause genuinely cancels the first reads as understatement and reaches for 但是 instead.