1. Meaning and Usage
In Chinese, to express how long an action lasts (the duration of time), we use the structure "Verb + 了 (le) + Duration" . This is used to indicate that an action was performed for a specific length of time.
Unlike English, where time duration can often be placed at the beginning or end of a sentence with prepositions like "for" (e.g., "I slept for eight hours"), Chinese places the duration directly after the verb and its completion particle 了 (le). No preposition is needed.
Depending on whether the verb has an object, and whether the action is still continuing into the present, this structure adapts into a few specific patterns.
2. Formulas and Examples
Case 1: Intransitive Verbs (Verbs without an Object)
When the verb does not take a direct object, the duration simply follows the verb and 了. This indicates a completed action that lasted for a specific period of time.
$$\text{Subject} + \text{Verb} + \text{了} + \text{Duration of Time}$$
我睡了八个小时。 Wǒ shuì le bā gè xiǎoshí. I slept for eight hours.
他们在外面跑了半个小时。 Tāmen zài wàimiàn pǎo le bàn gè xiǎoshí. They ran outside for half an hour.
Case 2: Transitive Verbs (With an Object) - Repeating the Verb
If the verb has an object, you cannot place the duration directly after the object. One common way to resolve this is to state the "Verb + Object" first, and then repeat the "Verb + 了 + Duration".
$$\text{Subject} + \text{Verb} + \text{Object} + \text{Verb} + \text{了} + \text{Duration of Time}$$
他上学期学汉语学了三个月。 Tā shàng xuéqī xué Hànyǔ xué le sān gè yuè. He studied Chinese for three months last semester.
我昨天看电视看了两个小时。 Wǒ zuótiān kàn diànshì kàn le liǎng gè xiǎoshí. I watched television for two hours yesterday.
Case 3: Transitive Verbs (With an Object) - The "的" Structure
An alternative, more casual way to handle objects is to place the duration between the verb and the object, often linking them with the particle 的 (de). This treats the duration as a modifier of the object (e.g., "three hours' worth of television").
$$\text{Subject} + \text{Verb} + \text{了} + \text{Duration of Time} + (\text{的}) + \text{Object}$$
我昨天看了两个小时的电视。 Wǒ zuótiān kàn le liǎng gè xiǎoshí de diànshì. I watched television for two hours yesterday.
妹妹听了半个小时 division 的音乐。 Mèimei tīng le bàn gè xiǎoshí de yīnyuè. My younger sister listened to music for half an hour.
Case 4: The "Double 了" Structure (Ongoing Actions)
If the action is still continuing at the moment of speaking, you must add a second 了 (le) at the very end of the sentence.
$$\text{Subject} + \text{Verb} + \text{了} + \text{Duration of Time} + (\text{Object}) + \text{了}$$
我学习了一年汉语了。 Wǒ xuéxí le yī nián Hànyǔ le. I have been studying Chinese for a year (and I am still studying it now).
他睡了十个小时了。 Tā shuì le shí gè xiǎoshí le. He has been sleeping for ten hours (and is still asleep).
3. Essential HSK Tips & Common Mistakes
Mistake 1: Placing the Duration Before the Verb
English speakers often translate "I worked for three hours" word-for-word, placing the time phrase before the verb. In Chinese, duration must go after the verb.
- Incorrect: 我三个小时工作了。(Wǒ sān gè xiǎoshí gōngzuò le.)
- Correct:
我工作了三个小时。 Wǒ gōngzuò le sān gè xiǎoshí. I worked for three hours.
Mistake 2: Mixing up "Time Word" (When) and "Duration Word" (How Long)
Time words (like 3 o'clock, Monday, yesterday) tell you when something happens and go before the verb. Duration words (like three hours, three days) tell you how long and go after the verb.
- Incorrect: 我看书了三点。(I read books for 3 o'clock.)
- Correct:
我下午三点看了书。 Wǒ xiàwǔ sān diǎn kàn le shū. I read books at 3 PM. (Point in time)
我看了三个小时的书。 Wǒ kàn le sān gè xiǎoshí de shū. I read books for three hours. (Duration of time)
HSK Tip: The Pronoun Exception Rule
If the object of the sentence is a personal pronoun (like 我 wǒ, 你 nǐ, 他 tā), you cannot use the "的" structure. Instead, the pronoun must go before the duration, and no verb repetition is required.
$$\text{Subject} + \text{Verb} + \text{了} + \text{Pronoun} + \text{Duration}$$
- Incorrect: 我等了半个小时你。(Wǒ děng le bàn gè xiǎoshí nǐ.)
- Correct:
我等了你半个小时。 Wǒ děng le nǐ bàn gè xiǎoshí. I waited for you for half an hour.