(不但)不/沒…反而…grammar point · tier 1 · counter-expectation 反而 (instead, the opposite happened)
Denies the expected outcome with 不/沒, then 反而 supplies its reverse — the opposite of what was looked for; 不但 may front the denial to play up the surprise.
What you would expect did not happen — the opposite did.
序 · The move
1Name the outcome the situation leads you to expect, and deny it with 不 or 沒 (沒 for a past/completed event, 不 for will or quality).Is there a clear expectation being broken? With no expectation to overturn, 反而 has nothing to flip against.
2Open the second clause with 反而 and state the outcome that is the opposite of the expected one.Is B the reverse of what was expected, not merely a different or extra fact? If B only adds on, the frame is 不但…還/也…, not this.
3Optionally front the denial with 不但 to heighten the surprise (不但不/沒…，反而…).
例 · Examples
1不小心打破了花瓶，爸爸不但not only (fronts the denial)沒罵我didn't scold me (the expected outcome, denied)，反而on the contrary; instead安慰我comforted me (the opposite outcome)。
I accidentally broke the vase, and Dad not only didn't scold me — instead he comforted me.
界 · Boundary
不但…還/也…
反而 turns to the opposite of what was expected; 不但…還/也… stacks a same-direction second fact on the first. 反而 reverses; 還/也 adds.
雖然…但是… concedes a fact then turns to a plain contrast; 反而 delivers the opposite of an expectation that the first clause has already denied. Concession turns the topic; 反而 turns the very outcome you predicted.
卻 marks any mild unexpected turn; 反而 is stronger, the result running counter to expectation, the opposite of what should follow. 卻 = however; 反而 = on the contrary.
他不但沒生氣，還笑了。 (還 adds same-direction where a reversal is meant) → 他不但沒生氣，反而笑了。 (反而 flips to the opposite of the expected anger)
雖然下雨，反而很涼快。 (反而 paired with a plain concession, no denied expectation) → 下雨了，天氣反而更涼快。 (the expected discomfort is overturned into the opposite)
爬山爬了一天，但他們反而很累。 (反而 fronting the expected outcome, not its reverse) → 爬山爬了一天，他們不覺得累，反而精神很好。 (deny the expected tiredness, then flip to its opposite)
English reaches for 'but' or 'however' for any turn; 反而 is narrower — it needs an expectation already denied and then delivers its opposite, so it answers to 'on the contrary / instead', not a general 'but'.