As Soon As (一...就)
一...就
一...就 (yī...jiù) means "as soon as A happens, B follows." It expresses an immediate or automatic connection between two events.
Pattern
Subject + 一 + Verb₁,(Subject) + 就 + Verb₂
Explanation
一...就 expresses that one action follows another immediately or inevitably. "As soon as I got home, it started raining" — 我一到家,就下雨了. The 一 marks the trigger event, and 就 marks the immediate result.
This pattern can describe one-time events in the past (我一看到她就笑了 — As soon as I saw her, I laughed), habitual patterns (他一紧张就说不出话来 — Whenever he gets nervous, he can't speak), or general truths (一到冬天就很冷 — As soon as winter comes, it gets cold).
The subjects of the two clauses can be the same or different. When they are the same, the subject usually appears only once at the beginning: 他一回家就看电视. When different, each clause has its own subject: 老师一说,学生们就明白了.
A common extension is using 一...就 to describe someone's quick ability or habit: 她一学就会 (She picks it up as soon as she studies it). This pattern feels very natural in Chinese and is used constantly in daily conversation.
Examples
我一到家就给你打电话。
Wǒ yī dào jiā jiù gěi nǐ dǎ diànhuà.
I'll call you as soon as I get home.
她一听到这个消息就哭了。
Tā yī tīng dào zhège xiāoxi jiù kū le.
She cried as soon as she heard the news.
他一紧张就说不出话来。
Tā yī jǐnzhāng jiù shuō bù chū huà lái.
Whenever he gets nervous, he can't speak.
天一黑,路上就没有人了。
Tiān yī hēi, lù shàng jiù méiyǒu rén le.
As soon as it gets dark, there's no one on the street.
这道菜她一学就会了。
Zhè dào cài tā yī xué jiù huì le.
She learned this dish right away (as soon as she tried).
Common Mistakes
Wrong
我一到家,就我给你打电话。
Correct
我一到家,就给你打电话。
When the subject is the same in both clauses, do not repeat it after 就.
Wrong
一我到家就打电话。
Correct
我一到家就打电话。
一 goes directly before the verb, not before the subject. Subject comes first.
Wrong
他一紧张就是说不出话来。
Correct
他一紧张就说不出话来。
Do not add 是 after 就. 就 connects directly to the verb.
Related Grammar Points
Practice vocabulary from these grammar patterns
Build your vocabulary with science-backed spaced repetition — 30 days free.
Start Practicing