Time Clauses: 在…以前/以后, 当…的时候

Chinese grammar · HSK 2 · 时间状语 · By Carson 木林森

Pattern 1: 在…以前 / 以后 — before/after a point in time - 在吃饭以前，请洗手。(Before eating, please wash your hands.) - 在学校以后，他去了商店。(After school, he went to the store.) - Note: 以前/以后 come AFTER the time reference, not before.

在 zài to exist; to be alive 以前 yǐ qián before 以后 yǐ hòu after 当 dāng (onom.) dong 的时候 de shí hòu

Pattern 2: 当…的时候 — at the time when…
- 当我很小的时候，住在北京。(When I was very young, I lived in Beijing.)
- Use 当 for simultaneous background situations.

❌ 以前吃饭，请洗手。(wrong — 以前 must come after the time noun/VP)
✅ 吃饭以前，请洗手。(correct simplified form without 在)

Worked examples

Chinese	Pinyin	English	What it shows
在睡觉以前，他喜欢看书。	Zài shuì jiào yǐ qián, tā xǐ huān kàn shū.	Before going to sleep, he likes to read.	在 + VP + 以前 = time clause before an action; main clause follows
下课以后，我们一起去吃饭，好吗？	Xià kè yǐ hòu, wǒ men yī qǐ qù chī fàn, hǎo ma?	After class, let's go eat together, OK?	VP + 以后 at start of sentence; main clause with proposal follows
当我们在学校的时候，老师给了我们很多作业。	Dāng wǒ men zài xué xiào de shí hòu, lǎo shī gěi le wǒ men hěn duō zuò yè.	When we were at school, the teacher gave us a lot of homework.	当…的时候 frames simultaneous background situation for main event

Produce this pattern without stopping to think about it. GraphChinese drills Time Clauses across 12 exercises and schedules the review that keeps it.

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Time Expressions as Adverbials

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