A2
How long you did it for
Where a length of time sits in a Chinese sentence, why it is not where the “when” goes, and the two ways to fit it around an object.
Chinese puts when something happened before the verb and how long it went on after it. Two kinds of time, two different places, and mixing them up is the mistake this page exists for.
我昨天学了三个小时。
Wǒ zuótiān xuéle sān ge xiǎoshí.
I studied for three hours yesterday.
昨天 sits before 学 because it says when. 三个小时 sits after it because it says how long. Both in one sentence, on either side of the verb, which is the clearest possible demonstration of the rule.
我学了昨天三个小时。
我昨天学了三个小时。
昨天 has been dragged after the verb to sit with the duration. It belongs in front, with the other time-and-place words.
With an object, the verb repeats
The duration wants to sit directly after the verb, and an object is already there — the same collision as with 得, solved the same way.
我学中文学了三年。
Wǒ xué Zhōngwén xuéle sān nián.
I studied Chinese for three years.
The other option is to slide the duration in front of the object, where it behaves like a description of the amount:
我学了三年中文。
Wǒ xuéle sān nián Zhōngwén.
I studied Chinese for three years.
Both are correct and both are common. The second is lighter and is what most people say; the first puts a little more weight on the three years.
Still going, or finished
Adding 了 at the end says it is still true — the years are not over.
我学了三年中文了。
Wǒ xuéle sān nián Zhōngwén le.
I’ve been studying Chinese for three years.
Without the final 了 it reads as a closed chapter: you studied for three years, and then presumably stopped. That second 了 is the change-of-state one, saying the situation stands as of now.
Not doing something for a length of time
The duration moves in front of the verb, which is the one place the rule reverses. Nothing happened, so there is no action for the time to trail after.
我三天没睡觉了。
Wǒ sān tiān méi shuìjiào le.
I haven’t slept for three days.
Asking
多长时间, or 多久 in speech, goes where the answer would.
你学了多长时间？
Nǐ xuéle duō cháng shíjiān?
How long did you study for?