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    Chinese Grammar

    Expressing "once … then …" with 一旦 (yídàn)

    HSK 4
    Condition
    Result & Consequence

    Structure

    一旦 + Condition，就 + Result

    Explanation

    一旦 means "once" or "if ever" and is used to introduce a hypothetical condition, often one with significant consequences. It emphasizes that when the condition is met, the result is certain or inevitable. The structure often pairs with 就 to indicate the immediate consequence.

    Examples

    • 一旦决定了，就不要后悔。

      yídàn juédìng le, jiù bú yào hòuhuǐ.

      Once you've made a decision, don't regret it.

    • 一旦错过这个机会，就很难再有了。

      yídàn cuòguò zhège jīhuì, jiù hěn nán zài yǒu le.

      Once you miss this opportunity, it will be hard to get another one.

    • 食物一旦变质，就不能再吃了。

      shíwù yídàn biànzhì, jiù bù néng zài chī le.

      Once food goes bad, it can no longer be eaten.