English needs a whole verb — "get," "become," "turn," "grow" — to say that a quality has shifted: it got dark, I put on weight, the child grew taller. Mandarin needs none of that. You take the adjective and add 了, and the adjective itself carries the "became" meaning: 天黑了 = "the sky has gotten dark." This is just the change-of-state 了₂ landing on a stative predicate — but it's worth its own page because the English instinct to reach for a "become" verb is so strong, and so wrong here. Remember that in Chinese adjectives already behave like verbs (你高 = "you are tall," no 是), so adding 了 to one is as natural as adding it to any other predicate.
Adjective + 了 = "got / became [adjective]"
The pattern is bare-simple: (subject) + adjective + 了. No copula, no "become," no auxiliary. The adjective plus 了 reports that the subject has entered that state.
| Adjective |
| English |
|---|---|---|
| 黑 (dark) | 天黑了 | it's gotten dark |
| 胖 (fat) | 我胖了 | I've put on weight |
| 高 (tall) | 长高了 | has grown taller |
| 冷 (cold) | 天冷了 | it's turned cold |
| 累 (tired) | 累了 | got tired |
| 老 (old) | 老了 | has aged |
| 好 (good/ready) | 好了 | it's fixed / all set now |
天黑了，我们回家吧。
tiān hēi le, wǒmen huí jiā ba
It's gotten dark, let's head home. (informal) — 黑了, the adjective 黑 plus 了, means 'became dark' with no 'get' verb.
你最近好像胖了一点。
nǐ zuìjìn hǎoxiàng pàng le yìdiǎn
You seem to have put on a little weight lately. (informal, can sound blunt) — 胖了 = 'has gotten fatter'.
孩子长高了不少。
háizi zhǎng gāo le bù shǎo
The kid's grown quite a bit taller. (neutral) — 高了 (via 长高) reports the change in height.
English "get + adjective" maps straight onto adjective + 了
The cleanest way to internalise this is a direct pairing: wherever English says get/become/turn/grow + adjective, Chinese says adjective + 了. Nothing goes in the "get" slot.
天气冷了，多穿点衣服。
tiānqì lěng le, duō chuān diǎn yīfu
It's turned cold, put on more clothes. (informal) — 'turn cold' = 冷了.
我累了，先去睡了。
wǒ lèi le, xiān qù shuì le
I've gotten tired, I'll go to bed. (informal) — 'get tired' = 累了.
这几年我妈老了很多。
zhè jǐ nián wǒ mā lǎo le hěn duō
My mom has aged a lot these past few years. (neutral) — 'grow old' = 老了.
The 好了 family: fixed, ready, recovered
A special star of this pattern is 好了 — literally "good/well + 了," i.e. "has become good." Depending on context it means ready, done, fixed, all set, or recovered from illness. It's one of the most-used two-syllable phrases in daily Chinese.
好了，别哭了，没事了。
hǎo le, bié kū le, méi shì le
There there, stop crying, it's all okay now. (informal) — 好了 soothes: 'things are okay now'; note the string of 了₂s each marking a change.
菜做好了，快来吃吧。
cài zuò hǎo le, kuài lái chī ba
The food's ready, come and eat. (informal) — 做好了 = 'has become done/ready'.
他的感冒好了。
tā de gǎnmào hǎo le
His cold has cleared up. (neutral) — 好了 here = 'has recovered'.
Do you need 变 ("change")? Usually not
Chinese does have a "become" verb, 变 (biàn, "to change"): 天变黑了 and 天气变冷了 are both perfectly correct and add a shade of "underwent a change." But 变 is optional — the plain adjective + 了 already says "became," so most of the time you leave it out. What you must never do is use 成为 (chéngwéi, "to become") before an adjective: 成为 takes a noun/role ("become a teacher"), never a quality. For the full map of become-verbs, see the become-verbs page.
天气变冷了，秋天到了。
tiānqì biàn lěng le, qiūtiān dào le
The weather's turned cold, autumn's here. (neutral) — 变 is optional here; 天气冷了 alone means the same.
Common Mistakes
1. Inserting a "become" verb (成为) before an adjective. 成为 needs a noun; a quality change is just adjective + 了.
❌ 天成为黑了。
Incorrect — 成为 takes a noun/role, not an adjective. Use 天黑了.
✅ 天黑了。
tiān hēi le
It's gotten dark. — the adjective plus 了 already means 'became dark'.
2. Dropping 了, losing the "became" reading. Bare 天黑 states a quality, not a change; without 了 there's no "got."
❌ 天黑。
Reads as 'the sky is dark' (flat statement) — for 'it's gotten dark' you need 了.
✅ 天黑了。
tiān hēi le
It's gotten dark. — 了 supplies the change.
3. Adding 是 before the adjective. Chinese adjectives are already verbs, so no 是 — with or without 了.
❌ 天是黑了。
Incorrect — adjectives take no 是. Use 天黑了.
✅ 天黑了。
tiān hēi le
It's gotten dark. — adjective + 了, never 是.
4. Using 很 + adjective when you mean the change. 我很胖 is a static "I'm (very) fat"; the change "I've put on weight" is 我胖了, with 了 and no 很.
❌ 我很胖。
Says 'I'm fat' (a state) — not 'I've gained weight'.
✅ 我胖了。
wǒ pàng le
I've put on weight. — 了 marks the change; drop the 很.
Key Takeaways
- Adjective + 了 means "has become / has gotten [adjective]" — it's the change-of-state 了₂ on a stative predicate.
- Wherever English needs get / become / turn / grow + adjective, Chinese just adds 了: 冷了, 累了, 老了, 长高了.
- No 是, no separate "become" verb is needed — adjectives already act as verbs.
- 好了 is a workhorse: "ready / done / fixed / recovered," all from "become good."
- 变 ("change") is an optional intensifier (天变冷了); 成为 is for nouns only, never adjectives.
- Distinguish state vs change: 我很胖 (I'm fat) versus 我胖了 (I've gained weight).
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- Sentence-Final 了 (le₂): Change of State / 'Now'HSK 1 — Sentence-final 了 (le₂) reports a NEW situation — 'now it's different': 下雨了 (it's started raining), 我懂了 (now I get it), 十二点了 (it's twelve now). It marks a change of state, not the completion of a verb.
- Becoming: 变 / 成为 / 当 (Change / Become)HSK 3 — English 'become' fans out into several Mandarin verbs: 变 (biàn) for a change of state, 变成 (biànchéng) to turn into a different thing, 成为 (chéngwéi) formal 'become a…', and 当 (dāng) for taking up a role or job.
- Adjectives Are Stative Verbs (No 是)HSK 1 — A Chinese adjective is a kind of verb — it predicates on its own, with NO copula 是 (shì). 她很高 'she is tall', 天气很好 'the weather is good', 这个太贵了 'this is too expensive' — never *她是高. 高 already means 'to be tall', so 是 has no job; negate with 不 (不高), not 没.
- Telling le₁ from le₂HSK 2 — The two 了s differ by position and meaning: 了₁ sits after the verb and marks a completed action (我买了票); 了₂ closes the sentence and marks a changed situation (我买票了). When the verb ends the sentence, one 了 does both (我吃饱了).