HSK 5 grammar · conjunction
除非
除非 — unless / only if
Pattern
+ +
+ +
( ) can be left out · other words may come before, between and after
How it works
Marks the sole condition under which something will happen. Paired with 否则/不然 it means 'unless X, otherwise…'; paired with 才 it means 'only if X will Y happen.' The condition is presented as the one and only exception.
Examples
除非你先道歉，否则他不会理你。
Chúfēi nǐ xiān dàoqiàn, fǒuzé tā bù huì lǐ nǐ.
Unless you apologize first, he won't pay any attention to you.
除非亲眼看到，我才会相信。
Chúfēi qīnyǎn kàndào, wǒ cái huì xiāngxìn.
Only if I see it with my own eyes will I believe it.
Related
See it in a story
In the app, 除非 is underlined wherever it appears in the stories you read, and practised with sentences from them. Free.