Introduction
一……就…… (yī … jiù …) chains two events so tightly that the second follows the moment the first is done: 我一到家就给你打电话。(Wǒ yí dào jiā jiù gěi nǐ dǎ diànhuà.) — I'll ring you as soon as I get home. It also covers "whenever" — the same frame, said about a habit.
Overview
Structure: (Subj.) + 一 (yī) + Verb 1，(Subj.) + 就 (jiù) + Verb 2
| Pattern | Example | Translation |
|---|---|---|
| 一 + V1 + 就 + V2（same subject） | 我一到家就睡了。(Wǒ yí dào jiā jiù shuì le.) | I went to bed as soon as I got home. |
| 一 + V1，Subj + 就 + V2 | 他一说，我就懂了。(Tā yì shuō, wǒ jiù dǒng le.) | The moment he explained, I got it. |
| 一 + V1 + 就 + V2（habit） | 我一喝咖啡就睡不着。(Wǒ yì hē kāfēi jiù shuì bu zháo.) | Coffee always keeps me awake. |
| 一 + Time + 就 | 一下课就走 (yí xiàkè jiù zǒu) | leave the moment class ends |
| 一……就……了 | 他一来就走了。(Tā yì lái jiù zǒu le.) | He left as soon as he arrived. |
一……就…… (yī … jiù …) is immediate; 每次……都…… (měi cì … dōu …) is only reliable:
- 我一到家就给你打电话。(Wǒ yí dào jiā jiù gěi nǐ dǎ diànhuà.) — The call follows straight away.
- 我每次到家都给你打电话。(Wǒ měi cì dào jiā dōu gěi nǐ dǎ diànhuà.) — I always ring, but not necessarily at once.
- 一 (yī) attaches to the first verb and 就 (jiù) to the second — neither may be dropped.
- The two clauses can have different subjects: 他一说，我就懂了。(Tā yì shuō, wǒ jiù dǒng le.)
Examples
我一到家就给你打电话。
Wǒ yí dào jiā jiù gěi nǐ dǎ diànhuà.
I'll ring you as soon as I get home.
他一说，我就懂了。
Tā yì shuō, wǒ jiù dǒng le.
The moment he explained it, I understood.
我一喝咖啡就睡不着。
Wǒ yì hē kāfēi jiù shuì bu zháo.
Whenever I drink coffee I can't sleep.
一下课他就走了。
Yí xiàkè tā jiù zǒu le.
He left the moment class finished.
我一看就知道是你写的。
Wǒ yí kàn jiù zhīdào shì nǐ xiě de.
One look and I knew you'd written it.
他一到北京就给家里打了电话。
Tā yí dào Běijīng jiù gěi jiā li dǎ le diànhuà.
He rang home as soon as he reached Beijing.
Usage Notes
- The tone of 一 (yī) follows the verb behind it, not 就: 一到 is yí dào，一说 is yì shuō，一看 is yí kàn，一喝 is yì hē.
- For a single future event the frame means "as soon as". Said about a habit, the same frame means "whenever": 我一喝咖啡就睡不着。(Wǒ yì hē kāfēi jiù shuì bu zháo.)
- When both halves share a subject, it is stated once, at the front: 我一到家就睡了。(Wǒ yí dào jiā jiù shuì le.)
- 了 (le) goes at the end if the whole thing has happened: 他一来就走了。(Tā yì lái jiù zǒu le.)
- This 就 (jiù) is the same one that marks earliness — 他六点就来了 (tā liù diǎn jiù lái le). Both say "sooner than you would expect".