How to Say “By the Time” and “When” in Chinese (等到)
等到 (děngdào) starts out as “wait until,” but as a conjunction it means “by the time / once / when a point is reached.” It leads the sentence with a time or event, then the main clause says what follows: 等(到) + Time / Event，(Subj) + 就 / 再 / 才 + Predicate. The second-clause adverb sets the tense: 就 / 再 look forward (等到夏天就会热, “when summer comes it’ll get hot”), while 才 marks a past “not until” (等我到家才发现, “not until I got home did I realize”). The 到 is optional (short form 等).
Why this trips learners up
The word 等 means “to wait,” and 等到 (děngdào) starts out as “wait until.” But it has a bigger job as a conjunction, and that’s how to say “by the time” or “when (a point is reached)” in Chinese: 等(到) + [Time / Event]，(Subj) + 就 / 再 / 才 + [Predicate]. It leads the sentence with the awaited time or event, then the main clause says what happens. The 到 is optional, so 等 and 等到 are both fine.
The second-clause adverb tells you the tense. This is the pattern’s real trick. For the future, the main clause takes 就 or 再: 等到夏天，天气就会热起来 (“when summer comes, the weather will get hot”), 等雨停了，我们再走 (“once the rain stops, we’ll go”). 就 means “right away,” 再 means “then / after that.”
For the past, the main clause takes 才. Here 等(到)…才… means “it wasn’t until X that Y happened,” with 才 marking how late it was: 等我到了家，才发现钥匙丢了 (“it wasn’t until I got home that I realized I’d lost my keys”), 等到孩子睡了，她才有空看书 (“not until the kids were asleep did she have time to read”). This past use overlaps 直到…才 (“all the way until”).
Don’t confuse 等到 with 的时候. 等到 marks reaching a point that then triggers the next thing (“by the time X, then Y”). 的时候 marks a backdrop span during which something else happens (“while / when,” 我小的时候, “when I was young”). “When I was young I lived in Beijing” is 我小的时候…, not 等到我小…. Reach a point, then react → 等到; a stretch of time you’re inside → 的时候.
The structure
Colour key
Each colour marks one grammatical role — and the same colour means the same role on every page in the Lab.
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.
děngdào 等到 Pattern xiàtiān 夏天 Time tiānqì 天气 Subject jiù 就 Adverb huì 会 Function word rè 热 Adjective qǐlái 起来 Function word
When summer comes, the weather will get hot. (Future, with 就.)
děng 等 Pattern yǔ 雨 Subject tíng 停 Verb le 了 Function word wǒmen 我们 Subject zài 再 Adverb zǒu 走 Verb ba 吧 Function word
Once the rain stops, let’s head out. (Future, 等 short form + 再.)
děngdào 等到 Pattern fā 发 Verb gōngzī 工资 Object wǒ 我 Subject jiù 就 Adverb bǎ 把 Function word qián 钱 Object huán gěi 还给 Verb nǐ 你 Object
When I get paid, I’ll pay you back. (Future, with 就.)
děng 等 Pattern wǒ 我 Subject dào 到 Verb le 了 Function word jiā 家 Place cái 才 Adverb fāxiàn 发现 Verb yàoshi 钥匙 Object diū 丢 Verb le 了 Function word
It wasn’t until I got home that I realized I’d lost my keys. (Past, with 才.)
děng 等 Pattern nǐ 你 Subject kǎo wán 考完 Verb shì 试 Object zài 再 Adverb hǎohāo 好好 Adverb xiūxi 休息 Verb jǐ tiān 几天 Time ba 吧 Function word
Once you finish your exams, take a good few days’ rest. (Future, with 再.)
děngdào 等到 Pattern háizi 孩子 Subject shuì 睡 Verb le 了 Function word tā 她 Subject cái 才 Adverb yǒu kòng 有空 Verb kàn 看 Verb shū 书 Object
It wasn’t until the kids were asleep that she had time to read. (Past, with 才.)
děng 等 Pattern tā 他 Subject zìjǐ 自己 Subject dāng 当 Verb le 了 Function word bàba 爸爸 Object cái 才 Adverb míngbai 明白 Verb fùmǔ 父母 Subject de 的 Function word bù 不 Negation róngyì 容易 Adjective
Not until he became a father himself did he understand how hard his parents had it. (Past, a late realization.)
děngdào 等到 Pattern suǒyǒu 所有 Adjective rén 人 Subject dōu 都 Adverb líkāi 离开 Verb le 了 Function word tā 他 Subject cái 才 Adverb gǎn 敢 Function word shuōchū 说出 Verb zhēnxiàng 真相 Object
Not until everyone had left did he dare tell the truth. (A longer past “not until.”)
Common mistakes
Why it happens: The second-clause adverb marks the tense. A PAST “not until” needs 才 (“only then”), not 就: 等我到了家，才发现钥匙丢了. 就 would make it sound immediate and expected, the opposite of “not until.”
Why it happens: 等到 leads the sentence with the time or event; the main clause (with 就 / 再 / 才) comes second. It’s 等到发工资，我就把钱还你, not the 等到 clause trailing at the end.
Why it happens: 等到 is for reaching a future or past POINT that triggers the next thing. A simultaneous backdrop (“when I was young”) is 的时候, not 等到: 我小的时候，住在北京, never 等到我小.
Compare & contrast
| 等(到)…，就 / 再 … = future (“when X, then Y”) | 等(到)…，才 … = past (“not until X did Y”) | The difference |
|---|---|---|
| 等他回来，我就告诉他。děng tā huílái, wǒ jiù gàosu tā. | 等他回来了，我才告诉他。děng tā huílái le, wǒ cái gàosu tā. | 等他回来，我就告诉他 looks forward (“when he’s back, I’ll tell him”). 等他回来了，我才告诉他 looks back (“I didn’t tell him until he came back”). Same opener, 就 for the future plan, 才 for the past delay. |
| 等下课，我们就走。děng xiàkè, wǒmen jiù zǒu. | 等下课了，我们才走。děng xiàkè le, wǒmen cái zǒu. | 等下课，我们就走 is a future intention (“once class ends, we’ll leave”). 等下课了，我们才走 is a past fact (“we didn’t leave until class ended”). The adverb after the comma flips the tense. |
Try it yourself
Say “When the holidays come, I’ll go traveling.” Use the future frame 等到 + Event，(Subj) + 就 + Predicate: 等到放假，我就去旅游。
Related patterns
Quick reference card
How to Say “By the Time” and “When” in Chinese (等到) grammar.merrymandarin.com A pocket summary — print it and keep it by your desk.