Conditions and immediacy
B1 条件复句（只要…就、只有…才、除非）与「一…就」 44 / 56
In short
Chinese splits “if” into two kinds. A sufficient condition (“this much is enough”) uses 只要……就 (zhǐyào……jiù, as long as); a necessary condition (“nothing less will do”) uses 只有……才 (zhǐyǒu……cái, only if). The whole contrast lives in the second-clause adverb: 就 = enough/soon, 才 = only then/not until. 除非 (chúfēi, unless) is a necessary condition too, and 一……就 (yī……jiù) times one event right after another - as soon as A, then B.
The rule
Step 1 - Sufficient vs necessary. English says “if” for both, but Chinese forces a choice. Is the condition enough on its own to guarantee the result (sufficient), or is it the only route to the result (necessary)? The opener tells you which, and the second clause confirms it with 就 or 才 - both adverbs, both sitting after the subject, before the verb (the same placement rule as in the Conditional, cause and concession lesson).
Step 2 - 只要……就 (sufficient). 只要 (zhǐyào, “as long as / so long as / provided that”) says one condition is enough; the result follows with 就 (jiù), which here means “then, and that’s all it takes.”
只要 + condition，(subject) + 就 + result
只要你努力，就会成功。 (zhǐyào nǐ nǔlì, jiù huì chénggōng) - As long as you work hard, you’ll succeed. The feel is generous: meet this low bar and the result is guaranteed.
Step 3 - 只有……才 (necessary). 只有 (zhǐyǒu, “only if / only when”) says the condition is the one and only way; without it, no result. The result clause takes 才 (cái, “only then, not until”), very often as 才能 / 才可以 (cái néng / cái kěyǐ, “can only then”).
只有 + condition，(subject) + 才 + result
只有多练习，才能学好中文。 (zhǐyǒu duō liànxí, cái néng xué hǎo Zhōngwén) - Only by practising a lot can you learn Chinese well. The feel is strict: nothing short of this will do. Do not swap in 就 here - 就 would wrongly say the condition is merely sufficient.
Step 4 - 除非 (unless). 除非 (chúfēi) marks the sole condition, so it behaves like 只有. It has two exits:
除非 + condition，才 + result (positive: only under this condition) 除非 + condition，否则 / 不然 + opposite result (negative: otherwise the reverse)
除非你道歉，我才原谅你。 (chúfēi nǐ dàoqiàn, wǒ cái yuánliàng nǐ) - I’ll forgive you only if you apologise (unless you apologise, I won’t). Or with the “otherwise” tail: 除非你道歉，否则我不原谅你 (…fǒuzé wǒ bù yuánliàng nǐ). Never pair 除非 with 就.
Step 5 - 一……就 (immediate succession). This one is about time, not condition: two events back to back, with no gap. 一 (yī) clips onto the first verb, 就 onto the second.
(Subject) + 一 + Verb 1，(subject) + 就 + Verb 2
我一到家就给你打电话。 (wǒ yí dào jiā jiù gěi nǐ dǎ diànhuà) - As soon as I get home, I’ll call you. It also states habits (“whenever A, B”): 他一喝酒就脸红 (tā yì hē jiǔ jiù liǎn hóng, he blushes the moment he drinks). Note the sandhi of 一: written yī in isolation, it is said yì before a 1st/2nd/3rd-tone syllable and yí before a 4th tone - hence yí dào but yì hē.
Forms & patterns
The four frames and the adverb each one demands:
| Frame | Pinyin | Type | Second-clause word |
|---|---|---|---|
| 只要……就 | zhǐyào……jiù | sufficient condition (enough) | 就 (jiù) |
| 只有……才 | zhǐyǒu……cái | necessary condition (the only way) | 才 (cái) |
| 除非……才 | chúfēi……cái | necessary / “unless” | 才 (cái) |
| 除非……否则/不然 | chúfēi……fǒuzé / bùrán | ”unless …, otherwise” | 否则 / 不然 |
| 一……就 | yī……jiù | immediate succession (as soon as) | 就 (jiù) |
Why the adverb changes - the heart of the lesson:
| Adverb | Signals | Bar | Sense |
|---|---|---|---|
| 就 (jiù) | condition is enough; result comes easily / at once | low | ”then, right away - that’s all it takes” |
| 才 (cái) | condition is the sole route; result is hard-won | high | ”only then, not until” |
Examples
- 只要你努力，就一定能成功。 (Zhǐyào nǐ nǔlì, jiù yídìng néng chénggōng.) - As long as you work hard, you’re sure to succeed.
- 只要有时间，我就去看你。 (Zhǐyào yǒu shíjiān, wǒ jiù qù kàn nǐ.) - As long as I have time, I’ll come see you.
- 只有多练习，才能学好中文。 (Zhǐyǒu duō liànxí, cái néng xué hǎo Zhōngwén.) - Only by practising a lot can you learn Chinese well.
- 只有满十八岁，才可以考驾照。 (Zhǐyǒu mǎn shíbā suì, cái kěyǐ kǎo jiàzhào.) - Only once you turn eighteen can you take the driving test.
- 除非你先道歉，我才会原谅你。 (Chúfēi nǐ xiān dàoqiàn, wǒ cái huì yuánliàng nǐ.) - Only if you apologise first will I forgive you.
- 除非下大雨，否则我们一定去。 (Chúfēi xià dà yǔ, fǒuzé wǒmen yídìng qù.) - Unless it pours, we’ll definitely go.
- 我一到家就给你打电话。 (Wǒ yí dào jiā jiù gěi nǐ dǎ diànhuà.) - As soon as I get home, I’ll call you.
- 他一喝酒就脸红。 (Tā yì hē jiǔ jiù liǎn hóng.) - He blushes the moment he drinks.
- 孩子一见到妈妈就哭了。 (Háizi yí jiàn dào māma jiù kū le.) - The child burst into tears as soon as he saw his mum.
- 只要不下雨，比赛就照常进行。 (Zhǐyào bú xià yǔ, bǐsài jiù zhàocháng jìnxíng.) - As long as it doesn’t rain, the match goes ahead as usual.
Common mistakes
- 只有努力，就能成功。 -> 只有努力，才能成功。 - 只有 marks a necessary condition, so its result clause takes 才 (only then), never 就.
- 只要你来，我才高兴。 -> 只要你来，我就高兴。 - 只要 is sufficient and pairs with 就; keep 才 for 只有 / 除非.
- 除非你努力，就能成功。 -> 除非你努力，才能成功。 (or 除非你努力，否则不能成功。) - 除非 is a necessary condition like 只有: pair it with 才, or flip to 否则 / 不然 plus the opposite. Never 除非……就.
- 他一喝酒脸红。 -> 他一喝酒就脸红。 - the 就 is obligatory; 一 alone does not complete the frame - it needs its 就 partner.
- 我到家一就打电话。 -> 我一到家就打电话。 - 一 goes directly before the first verb and 就 before the second; don’t reorder them or let the object split the pair.
Tips
- The whole lesson is one split: enough -> 就, only -> 才. 只要……就 = “just this much is enough” (low bar, result comes easily); 只有……才 = “nothing less will do” (high bar, result comes only after). Match the adverb to the logic and the rest follows.
- Memory hook for the adverbs, straight from Scope and time adverbs (就/才/再/又/还): 就 is generous and fast (result arrives right away), 才 is grudging and late (result arrives only at last). Same personalities, now doing conditions.
- 除非 is 只有 in disguise - it names the sole condition. Two clean exits: 除非……才 (then the result) or 除非……否则/不然 (otherwise the reverse). Pairing 除非 with 就 is the classic slip.
- 一……就 is about timing, not “if”: two verbs, no gap. It doubles as a “whenever” for habits (他一累就睡, tā yí lèi jiù shuì, he sleeps the moment he’s tired). Remember the 一 sandhi - yì before tones 1/2/3, yí before a 4th tone.