Expressing "once...then..." with "yidan...jiu..."

一旦 (yīdàn) is used to express what would happen after a certain condition is met. Usually it is used with 就. This grammar pattern expresses that "once" one thing happens, "then" something else will happen.

Structure

This structure is similar to the English "once... then," as in "once I get my hands on you, you'll wish you'd never been born."

一旦 + Condition，Subj. + 就 + Consequence

Examples

• 一旦 发生 事故，你 要 负责！Yīdàn fāshēng shìgù, nǐ yào fùzé!In case of an accident, you're responsible!
• 有些 人 一旦 有 了 钱，就 变了。Yǒuxiē rén yīdàn yǒu le qián, jiù biàn le.Some people change as soon as they have money.
• 一旦 你 的 公司 上市，你 就 可以 变成 有钱人。Yīdàn nǐ de gōngsī shàngshì, nǐ jiù kěyǐ biànchéng yǒuqiánrén.Once your company goes public, you'll be a rich man.
• 这 张 桌子 不 稳定，一旦 发生 什么 小小的 振动，就 会 倒塌。Zhè zhāng zhuōzi bù wěndìng, yīdàn fāshēng shénme xiǎoxiǎo de zhèndòng, jiù huì dǎotā.This table isn't very stable. If there's even a small vibration, it will fall over.
• 学习 计算机 科学 的 学生 很 自信，他们 一旦 毕业，就 会 找到 很 好 的 工作。Xuéxí jìsuànjī kēxué de xuéshēng hěn zìxìn, tāmen yīdàn bìyè, jiù huì zhǎodào hěn hǎo de gōngzuò.Computer science students are very confident. Once they graduate, they will be able to find good jobs.
• 千万 不 要 在 经济 泡沫 中 炒股，一旦 市场 崩溃，你 会 很 后悔 的！Qiānwàn bùyào zài jīngjì pàomò zhōng chǎogǔ, yīdàn shìchǎng bēngkuì, nǐ huì hěn hòuhuǐ de!You absolutely must not trade stocks in an economic bubble. Once the market collapses, you will regret it!
• 一旦 做出 决定，就 没有 借口，只有 认真 去 做。Yīdàn zuòchū juédìng, jiù méiyǒu jièkǒu, zhǐyǒu rènzhēn qù zuò.Once a decision is made, there are no more excuses, and all you can do is take it seriously and do it.
• 人 一旦 在 一个 很 舒服 的 环境 中，就 不想 继续 努力 了。Rén yīdàn zài yī gè hěn shūfu de huánjìng zhōng, jiù bù xiǎng jìxù nǔlì le.Once you're in a comfortable environment, you don't want to keep trying.
• 一旦 提高 价格，你 会 失去 很多 客户的。Yīdàn tígāo jiàgé, nǐ huì shīqù hěn duō kèhù de.If you raise your prices, you will lose a lot of customers.
• 这种 病 很 复杂，一旦 染上，很 难 治好。Zhè zhǒng bìng hěn fùzá, yīdàn rǎnshàng, hěn nán zhì hǎo.This disease is very complicated and once you've contracted it, it's hard to cure.

Notice that in a few of the examples there is no 就. Sometimes you can leave out the 就 and the context that the result will happen is pretty clear.

Sources and further reading

Books

• New Practical Chinese Reader 3 (新实用汉语课本3) (pp. 83) Anything Goes (无所不谈) →buy
• Common Chinese Patterns 330 (汉语常用格式330例) (pp. 262) Anything Goes (无所不谈) →buy

HSK5