“About to Happen”: the Future 了 (快…了 / 要…了)
了 isn’t only for the past! Paired with 快, 快要, or 要, the sentence-final 了 says something is about to happen: 快下雨了 (“it’s about to rain”), 火车要开了 (“the train’s about to leave”), 天快黑了 (“it’s almost dark”). The 了 marks the imminent change.
Why this trips learners up
One of the most freeing things to learn about 了: it is not just a past marker. With the right partner, the sentence-final 了 points to the near future — something that’s about to happen. The partner is one of 快 / 快要 / 要, and the 了 sits at the end: 快下雨了 (“it’s about to rain”), 飞机快要起飞了 (“the plane’s about to take off”), 超市要关门了 (“the supermarket’s about to close”).
The three markers are basically interchangeable. 快 + Verb/Adj + 了 leans toward “almost / soon” — great with adjectives: 天快黑了 (“it’s almost dark”), 我的手机快没电了 (“my phone’s nearly dead”). 快要 + Verb + 了 and 要 + Verb + 了 lean toward “about to”: 火车要开了, 孩子快要睡着了. You’ll also meet 就要 + Verb + 了, often with a set time: 我们就要毕业了 (“we’re about to graduate”).
Two things to hold onto. First, the meaning lives in that final 了 — drop it and the “about to” evaporates (快下雨了, not 快下雨). Second, this is the change-of-state 了 you already know — “a new situation” — just pointed forward in time instead of back. And 要 here means “about to,” not “want”: 天要黑了 is “it’s about to get dark,” not “the sky wants to be dark.”
One caution: 快…了 / 要…了 mean something is imminent — coming right up. So they don’t pair with a far-off time word. “I’m about to graduate” is 我快毕业了, but for next year you’d just say 我明年毕业.
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.
diànyǐng 电影 Subject kuài 快 Pattern kāishǐ 开始 Verb le 了 Pattern
The movie’s about to start (快 + verb + 了).
wǒ de shǒujī 我的手机 Subject kuài 快 Pattern méi diàn 没电 Adjective le 了 Pattern
My phone’s almost dead (快 + adjective).
fēijī 飞机 Subject kuàiyào 快要 Pattern qǐfēi 起飞 Verb le 了 Pattern qǐng 请 Verb guān 关 Verb shǒujī 手机 Object
The plane’s about to take off — please turn off your phone (快要 + verb).
nǐ kàn 你看 Verb yuèliang 月亮 Subject kuàiyào 快要 Pattern chūlái 出来 Verb le 了 Pattern
Look, the moon’s about to come out (快要 + verb).
kuài zuò hǎo 快坐好 Verb huǒchē 火车 Subject yào 要 Pattern kāi 开 Verb le 了 Pattern
Sit down quick, the train’s about to leave (要 + verb).
wǒ 我 Subject yào 要 Pattern è sǐ 饿死 Adjective le 了 Pattern wǒmen 我们 Subject kuài 快 Adverb qù 去 Verb chīfàn 吃饭 Verb ba 吧 Function word
I’m starving — let’s go eat (要 + adjective, 饿死 “about to starve”).
wǒmen 我们 Subject jiù yào 就要 Pattern bìyè 毕业 Verb le 了 Pattern zhēn 真 Adverb shěbude 舍不得 Verb
We’re about to graduate — I really can’t bear to leave (就要 + verb).
dōu 都 Adverb shíyī diǎn 十一点 Time le 了 Function word háizi 孩子 Subject kuàiyào 快要 Pattern shuìzháo 睡着 Verb le 了 Pattern
It’s already 11 — the kid’s about to fall asleep (快要 + verb).
Common mistakes
Why it happens: The “about to” meaning is carried by the final 了 — don’t drop it. 快下雨了 (“it’s about to rain”), not 快下雨. 快 / 要 set it up, but 了 is what closes the imminent change.
Why it happens: 快…了 / 要…了 mean something is imminent — right around the corner — so they clash with a distant time word. “I’m about to graduate” is 我快毕业了; for next year, just say 我明年毕业 (no 快…了).
Why it happens: The marker (快 / 要) goes right before the verb, and 了 ends the sentence: 超市要关门了, not 要超市关门了. The subject stays in front of 要.
Compare & contrast
| 快/要 + … + 了 — about to happen (not yet) | 已经 + … + 了 — already happened (done) | The difference |
|---|---|---|
| 电影快开始了diànyǐng kuài kāishǐ le | 电影已经开始了diànyǐng yǐjīng kāishǐ le | 电影快开始了 = “the movie’s about to start” (any second now). 电影已经开始了 = “the movie’s already started.” Both end in 了; opposite sides of now. |
| 他要走了tā yào zǒu le | 他已经走了tā yǐjīng zǒu le | 他要走了 = “he’s about to leave”; 他已经走了 = “he’s already left.” 快/要 points forward, 已经 points back. |
Try it yourself
Say “The train’s about to leave.” — 要 before the verb, 了 at the end.
Related patterns
Quick reference card
“About to Happen”: the Future 了 (快…了 / 要…了) grammar.merrymandarin.com A pocket summary — print it and keep it by your desk.