Level 4 · Upper Intermediate
Unless: 除非…才/否则
除非 A，Subj. + 才 B / 除非 A，否则 B · Traditional: 除非 A，Subj. + 才 B / 除非 A，否則 B
除非 (chúfēi) names the ONE condition that changes everything: 除非你去，我才去 "only if you go will I go — otherwise I won't". In the main clause it pairs with 才.
The other partner is 否则 "otherwise": 除非下雨，否则我们明天去爬山 "unless it rains, we're going hiking tomorrow". So: 除非 A，才 B means B happens only with A; 除非 A，否则 B means without A, B goes ahead anyway. What 除非 never pairs with is 就.
Examples
除非你去，我才去。
chú fēi nǐ qù wǒ cái qù
I'll only go if you go.
除非下雨，否则我们明天去爬山。
除非下雨，否則我們明天去爬山。
chú fēi xià yǔ fǒu zé wǒ men míng tiān qù pá shān
Unless it rains, we're going hiking tomorrow.
除非他先说对不起，我才会原谅他。
除非他先說對不起，我才會原諒他。
chú fēi tā xiān shuō duì bù qǐ wǒ cái huì yuán liàng tā
I'll forgive him only if he apologizes first.
这件事除非你告诉他，否则他不会知道。
這件事除非你告訴他，否則他不會知道。
zhè jiàn shì chú fēi nǐ gào sù tā fǒu zé tā bù huì zhī dào
Unless you tell him, he'll never know about this.
Common mistakes
✗ 除非你去，我就去。
✓ 除非你去，我才去。
除非 pairs with 才 or 否则 — 就 belongs to 只要 and 如果.
Related grammar points
Practice this pattern in graded stories like The Cat's Conditions (Part 1) inside the Literate Chinese app.
