一旦…就…
HSK 5- Conditionals
Structure (结构 jiégòu)
Meaning (意思 yìsi)
The structure 一旦…就… expresses a conditional relationship: once the first action occurs, the second action will immediately follow.
Explanation (解释 jiěshì)
The paired conjunction 一旦…就… (yīdàn…jiù…) is used to express a tight condition-result relationship. 一旦 introduces a hypothesis or condition, while 就 leads to the result that immediately follows. This structure emphasizes that once the condition is met, the result will inevitably occur. It is equivalent to "once…then…" or "as soon as…then…" in English.
Examples (例句 lìjù)(5)
- 一旦开始，就不能停下来。繁: 一旦開始，就不能停下來。Yīdàn kāishǐ, jiù bùnéng tíng xiàlái.
Once you start, you cannot stop.
- 他一旦喝了酒，话就特别多。繁: 他一旦喝了酒，話就特別多。Tā yīdàn hē le jiǔ, huà jiù tèbié duō.
Once he drinks alcohol, he becomes particularly talkative.
- 这个问题一旦出现，就很难解决。繁: 這個問題一旦出現，就很難解決。Zhège wèntí yīdàn chūxiàn, jiù hěn nán jiějué.
Once this problem appears, it becomes very difficult to resolve.
- 你一旦决定了，就不要后悔。繁: 你一旦決定了，就不要後悔。Nǐ yīdàn juédìng le, jiù bùyào hòuhuǐ.
Once you have made a decision, do not regret it.
- 电脑一旦中毒，文件就会丢失。繁: 電腦一旦中毒，文件就會丟失。Diànnǎo yīdàn zhòngdú, wénjiàn jiù huì diūshī.
Once a computer gets infected with a virus, files will be lost.
Common mistakes
- Wrong:他一旦回家，看电视。Correct:他一旦回家，就看电视。
This is a paired structure. `一旦` introduces a condition and `就` must accompany it to indicate the result that follows immediately after.
- Wrong:如果一旦下雨，我们就不去了。Correct:一旦下雨，我们就不去了。
Both 一旦 and 如果 indicate conditions, but 一旦 already implies "once" or "as soon as," so they should not be used together.