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How to Say “As Soon As” in Chinese (一……就)

One frame links two events: 一 marks the trigger, 就 marks what follows right after. (Subject) + 一 + Event1,就 + Event2. It reads as “as soon as” for a one-time sequence (我一到家就睡了, “as soon as I got home, I slept”) and as “every time / whenever” for a habit (我一紧张就忘词, “every time I get nervous, I forget my words”). Both 一 and 就 are required, and 一 sits right before Event 1’s verb.

Why this trips learners up

Chinese ties two events together with a single frame, and it handles both “as soon as” and “every time” at once. That is the trick to how to say “as soon as” in Chinese: (Subject) + 一 + Event 1,就 + Event 2. 一 flags the trigger; 就 says the second thing follows immediately. So 我一到家就睡了 is “as soon as I got home, I went to sleep,” and 你一到就给我打电话吧 is “call me as soon as you arrive.”

The same frame also means “every time / whenever.” When the two events are a recurring pattern rather than a single occasion, 一 reads as “whenever”: 他一喝咖啡就睡不着 (“every time he drinks coffee, he can’t sleep”), 我一紧张就忘词 (“whenever I get nervous, I forget my words”). English uses two different phrases here, “as soon as” versus “every time,” but Chinese uses one 一…就 and lets context decide. A one-off in the past usually ends in 了; a habit takes no 了.

The two events can share a subject or not. If they share one, don’t repeat it: 他一看到我就笑了 (“as soon as he saw me, he smiled”). If the subjects differ, each clause keeps its own: 我一说完,大家就鼓掌了 (“as soon as I finished, everyone applauded”), with 就 sitting right before the second subject’s verb.

Three mechanics matter. Both halves are obligatory, you can’t drop 就 and lean on 一 alone. 一 goes after the subject and right before Event 1’s verb (我一下课, never 一我下课). And don’t put 了 on Event 1: it is 一下课, not 一下课了; any 了 for a completed one-off rides Event 2 (一到家就睡了).

The structure

Subject 一 yī Verb 就 jiù Verb
Colour key

Each colour marks one grammatical role — and the same colour means the same role on every page in the Lab.

Pattern Subject Verb Object Time Function word Adjective Question

Examples in context

Real-world sentences, easiest first. Toggle pinyin or the translation, tap any word to see its role, or play the audio.

Tap a word to see its grammatical role.

wǒ 我 Subject yí 一 Pattern dào jiā 到家 Verb jiù 就 Pattern shuì 睡 Verb le 了 Function word

As soon as I got home, I went to sleep. (One-time sequence, ending in 了.)

tā 他 Subject yí 一 Pattern kàndào 看到 Verb wǒ 我 Object jiù 就 Pattern xiào 笑 Verb le 了 Function word

As soon as he saw me, he smiled. (Same subject; Event 1 has an object.)

tā 他 Subject yì 一 Pattern hē 喝 Verb kāfēi 咖啡 Object jiù 就 Pattern shuì bù zháo 睡不着 Verb

Every time he drinks coffee, he can’t sleep. (Habitual reading, no 了.)

wǒ 我 Subject yì 一 Pattern shuōwán 说完 Verb dàjiā 大家 Subject jiù 就 Pattern gǔzhǎng 鼓掌 Verb le 了 Function word

As soon as I finished speaking, everyone applauded. (Different subjects: 我 then 大家.)

nǐ 你 Subject yí 一 Pattern dào 到 Verb jiù 就 Pattern gěi 给 Verb wǒ 我 Object dǎ 打 Verb diànhuà 电话 Object ba 吧 Function word

Call me as soon as you arrive. (A future request, with 吧.)

wǒ 我 Subject yì 一 Pattern jǐnzhāng 紧张 Adjective jiù 就 Pattern wàng 忘 Verb cí 词 Object

Every time I get nervous, I forget my words. (Event 1 is a state, 紧张.)

zhège háizi 这个孩子 Subject yí 一 Pattern dào 到 Verb wǎnshang 晚上 Time jiù 就 Pattern kū 哭 Verb

This kid cries every evening. (一到 + a time word: “as soon as evening comes.”)

nǐ 你 Subject zěnme 怎么 Question yí 一 Pattern fàngjià 放假 Verb jiù 就 Pattern shēngbìng 生病 Verb

How come you get sick every time there’s a holiday? (Habitual, inside a 怎么 question.)

Common mistakes

Avoid: 我一下课去吃饭。 wǒ yí xiàkè qù chī fàn.
Say this: 我一下课就去吃饭。 wǒ yí xiàkè jiù qù chī fàn.

Why it happens: The pattern is a PAIR: 一 sets up the trigger, 就 delivers the immediate result. Drop 就 and it is incomplete, so it is 我一下课就去吃饭, not 我一下课去吃饭.

Avoid: 一我下课就吃饭。 yì wǒ xiàkè jiù chī fàn.
Say this: 我一下课就吃饭。 wǒ yí xiàkè jiù chī fàn.

Why it happens: 一 comes AFTER the subject and right before Event 1’s verb: 我一下课. Putting it in front of the subject (一我下课) is wrong. Same for 就, which sits right before Event 2’s verb.

Avoid: 我一下课了就去吃饭。 wǒ yí xiàkè le jiù qù chī fàn.
Say this: 我一下课就去吃饭。 wǒ yí xiàkè jiù qù chī fàn.

Why it happens: Don’t put 了 on Event 1. It is 一下课, never 一下课了; the 一 clause names the trigger, not a completed event. Any 了 for a one-time result goes on Event 2 or the sentence end: 一到家就睡了.

Compare & contrast

一…就 = “as soon as” (one time)一…就 = “every time” (a habit)The difference
我一到家就睡了。wǒ yí dào jiā jiù shuì le.我一到家就想睡。wǒ yí dào jiā jiù xiǎng shuì.我一到家就睡了 is a single past event (“as soon as I got home, I slept”), marked by 了. 我一到家就想睡 is a habit (“every time I get home, I want to sleep”), with no 了. Same frame, the 了 and the context set the reading.
他一来我就走了。tā yì lái wǒ jiù zǒu le.他一来我就紧张。tā yì lái wǒ jiù jǐnzhāng.他一来我就走了 reports one occasion (“as soon as he came, I left”). 他一来我就紧张 is a standing pattern (“every time he comes, I get nervous”). One-off versus recurring, told apart by 了 and context.
Rule of thumbThe same frame 一 + Event1,就 + Event2 has two readings. For a ONE-TIME sequence (“as soon as X, Y happened”) the sentence usually ends in 了: 我一到家就睡了. For a HABIT (“every time X, Y happens”) there is no 了 and Y is a general truth: 我一紧张就忘词. Context and the 了 decide.

Try it yourself

Say “As soon as class ends, I go home.” Use (Subject) + 一 + Event1,就 + Event2: 我一下课就回家。

Related patterns

Quick reference card
Merry Mandarin How to Say “As Soon As” in Chinese (一……就) grammar.merrymandarin.com

A pocket summary — print it and keep it by your desk.

Structure
Subject + 一 + Verb + 就 + Verb
Example
我一到家就睡了
As soon as I got home, I went to sleep. (One-time sequence, ending in 了.)
Watch out
✗ 我一下课去吃饭。  →  ✓ 我一下课就去吃饭。