不...不... for “If Not …, Then Not …”
In condensed sentences, 不 A 不 B means “if not A, then not B”: 不见不散, 不去不行, 雨不停我们不出发.
句型
不 + A + 不 + B (= if not A, then not B)
This 不……不…… packs a whole “if” sentence into a few words: 不见不散 means “if we don’t meet, we won’t leave,” and 不去不行 means “not going won’t do,” so you have to go. Two negatives often add up to a strong “must.”
这件事很重要，你不去不行。
When to use 不...不... for “If Not …, Then Not …”
A condensed sentence (紧缩复句) is a two-clause idea said without a comma or linking words. In 不 A 不 B, the first part is a condition and the second a result: “if not A, then not B.” 雨不停我们不出发 means “we won’t set off until the rain stops.” When B is 行 or 可以, the meaning becomes “must”: 不去不行 “I have to go.”
明天下午三点，我们在学校门口见，不见不散！
Tomorrow at three, we’ll meet at the school gate. See you there, no matter what!
雨不停我们不出发。
We won’t set off until the rain stops.
你不来我不走，我一直在这儿等你。
I won’t leave until you come; I’ll wait here for you.
这个字我不查词典不会写。
I can’t write this character without looking it up in a dictionary.
常见误区
- Don’t confuse it with 不大不小 (neither … nor …): here the first 不 part is a condition.
- 不去不行 means you must go, not that you can’t go.
- Write the tone change: 不见 bú jiàn, 不去 bú qù, 不散 bú sàn.
针对性练习
先练这个句式，再继续往下看。