Duration Complements: How Long an Action Lasts | Chinese (Mandarin) Grammar

English lets you say "for three years" almost anywhere — "For three years I studied Chinese," "I studied Chinese for three years." Chinese is far stricter: a duration phrase (时量补语, how long an action lasts) must sit after the verb, never before it. 学了三年 "studied for three years," 睡了八个小时 "slept eight hours," 等了半天 "waited ages." The length is a complement — it completes the verb by measuring the span of the action, much the way a frequency phrase measures how many times. This page fixes the position in place, then handles the one real complication: what to do when the verb also has an object.

Duration sits after the verb, with 了

The core frame is Verb + 了 + duration. The 了 marks the span as a completed, bounded stretch (see 了 as perfective), and the length phrase follows it directly. There is no preposition — no equivalent of English "for."

我昨天睡了八个小时，还是很累。

wǒ zuótiān shuì le bā ge xiǎoshí, háishì hěn lèi

I slept eight hours last night and I'm still tired. (informal) — 睡了 + 八个小时.

我们聊了两个小时，一点儿都不觉得累。

wǒmen liáo le liǎng ge xiǎoshí, yìdiǎnr dōu bù juéde lèi

We chatted for two hours and didn't feel tired at all. (informal) — 聊了 + 两个小时.

我等了半天，公交车还没来。

wǒ děng le bàntiān, gōngjiāochē hái méi lái

I waited ages and the bus still hadn't come. (informal) — 半天 literally 'half a day', an idiom for 'a long while'.

Note 半天 ("half a day") in that last one: it's a fixed, informal way to say "ages," not a precise measurement. Duration phrases can be exact (三年, 八个小时) or vague (半天, 一会儿 "a moment"); either way, they follow the verb.

When there's an object: 的 or copy the verb

Here is the wrinkle. If the verb has an object, the object competes with the duration for the slot right after the verb — the same clash you meet with the manner 得 complement. Chinese offers two clean fixes.

Strategy	Example	Notes
Insert 的 before the object	学了三年的中文	duration modifies the object like a measure phrase
Copy the verb	学中文学了三年	first 学 takes 中文, copy takes 了 + duration
Pronoun object first	等了你一个小时	light pronoun clings to the verb, duration follows
Object right after verb+了	学了中文三年	❌ noun object can't strand the duration

我学了三年的中文，可是还不太会说。

wǒ xué le sān nián de Zhōngwén, kěshì hái bú tài huì shuō

I've studied Chinese for three years, but I still can't really speak it. (informal) — 的 before the object 中文.

他昨晚看电视看了三个小时。

tā zuówǎn kàn diànshì kàn le sān ge xiǎoshí

He watched TV for three hours last night. (informal) — verb copied: 看电视 … 看了三个小时.

With a pronoun object the situation is easier: pronouns are light and stay glued to the verb, so the duration simply comes after them.

他等了你一个小时，你怎么才来？

tā děng le nǐ yí ge xiǎoshí, nǐ zěnme cái lái

He waited a whole hour for you — why are you only getting here now? (informal) — pronoun 你 before the duration.

💡

With a noun object, the smoothest choice is 的: 看了三个小时的电视, 学了三年的中文 — treat the duration like a quantity phrase modifying the object. Reserve the verb-copy for when you want to foreground the activity itself. With a pronoun object, neither trick is needed: 等了你一个小时.

Duration (how long) vs. time-when (at what point)

English handles both "how long" and "at what time" after the verb — "I studied for three years," "I came at three." Chinese splits them onto opposite sides of the verb: a time-when phrase goes before the verb, a duration phrase goes after. Mixing these up is the deepest source of word-order errors here.

我们八点开会，开了三个小时。

wǒmen bā diǎn kāihuì, kāi le sān ge xiǎoshí

We started the meeting at eight and it ran three hours. (neutral) — 八点 (when) before the verb, 三个小时 (how long) after it.

他昨天来的，在这儿住了两天。

tā zuótiān lái de, zài zhèr zhù le liǎng tiān

He arrived yesterday and has stayed here two days. (informal) — 昨天 (when) before, 两天 (how long) after.

That single sentence — 八点开会 (before) but 开了三个小时 (after) — is the whole rule in miniature. If a phrase answers "when?", it precedes the verb; if it answers "for how long?", it follows.

Common Mistakes

1. Putting the duration before the verb. A direct calque of "for three years I studied." In Chinese the length always follows the verb.

❌ 我三年学了中文。

Broken — the duration can't precede the verb; it goes after.

✅ 我学了三年中文。

wǒ xué le sān nián Zhōngwén

I studied Chinese for three years. — duration after the verb.

2. Stranding a noun object between the verb and the duration. Insert 的 or copy the verb instead.

❌ 我看了电视三个小时。

Broken — the noun object can't split verb+了 from the duration.

✅ 我看了三个小时的电视。

wǒ kàn le sān ge xiǎoshí de diànshì

I watched TV for three hours. — 的 before the object (or copy: 看电视看了三个小时).

3. Putting the duration before a pronoun object. With pronouns the order is verb + pronoun + duration.

❌ 他等了一个小时你。

Broken — the pronoun 你 comes before the duration: 等了你一个小时.

✅ 他等了你一个小时。

tā děng le nǐ yí ge xiǎoshí

He waited for you an hour. — pronoun before the length.

4. Dropping 了 on a completed span. For a bounded stretch that happened, the verb normally needs 了; the bare verb reads as habitual or future.

❌ 昨天我们聊两个小时。

Wrong aspect — a completed span needs 了: 聊了两个小时.

✅ 昨天我们聊了两个小时。

zuótiān wǒmen liáo le liǎng ge xiǎoshí

Yesterday we chatted for two hours. — 了 marks the completed span.

Key Takeaways

A duration phrase (how long) sits after the verb, with 了: 睡了八个小时, 学了三年, 等了半天.
There is no "for" — the length attaches directly, no preposition.
With a noun object, insert 的 (学了三年的中文) or copy the verb (学中文学了三年); never strand the object between the verb and the length.
With a pronoun object, just put it first: 等了你一个小时.
Keep duration (after the verb) apart from time-when (before the verb): 八点开会 … 开了三个小时.

Now practice Chinese

Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.

Start learning Chinese→