The Time-measure Complement
The time-measure complement (时量补语) shows the duration of an action.
Forming the time-measure complement
Pay attention
A complement is a secondary part of a sentence. It is placed after a predicate expressed by a verb or adjective, and expresses the speaker's view of the chance of success.
The time-measure complement is usually expressed by a numeral + classifier or by a numeral + noun that indicates a period of time: one hour, one year, one day.
The time-measure complement is placed after the verb. When an action takes place in the past, the verb is followed by the particle 了 
.
.Scheme
subject
predicate
(了)
complement
Examples
我每天锻炼一个小时
I exercise an hour a day
wǒ měi tiān duànliàn yí ge xiǎoshí
他们已经忙了两天
They've been busy for two days
tāmen yǐjīng máng le liǎng tiān
Pay attention
The aspect particle 着 and the words indicating that the action is taking place at the moment cannot be used with the time-measure complement.
For example:
正在
呢
and the words indicating that the action is taking place at the moment cannot be used with the time-measure complement.
For example:
正在
呢 If a verb is followed by an object
If a verb is followed by an object or the predicate is expressed by a verb-object structure, there are two options:
1) the complement is placed between the verb and the object. The complement may be followed by the particle 的 .
. Pay attention
In a verb-object structure, the verb is the verb part and the object is the nominal part. For example, in 吃饭 the verb is 吃 "to eat", and the object is 饭 "food".
the verb is 吃 "to eat", and the object is 饭 "food".Scheme
verb
(了)
complement
(的)
object
Examples
我学了五年汉语
I studied Chinese for five years
wǒ xué le wǔ nián hànyǔ
我们得排一个小时的队
We have to stand in line for an hour
我只睡了五个小时的觉
I only slept five hours
wǒ zhǐ shuìle liù ge xiǎoshí de jiào
However, if the object in a sentence is a person, it can only be placed after the verb. In this case, the time-measure complement is placed after the object, at the end of a sentence.
Examples
我们等了你半个小时
We've been waiting for you for half an hour
wǒmen děng le nǐ bàn ge xiǎoshí
2) the verb part is doubled.
In this case, 了follows the second verb.
Adverbs or modal verbs are also placed before the second verb.
Scheme
verb
object
verb
(了)
complement
Examples
我学汉语学了五年
I have studied Chinese for five years
wǒ xué hànyǔ xué le wǔ nián
我看书看了一个小时
I read the book for one hour
wǒ kàn shū kàn le yí ge xiǎoshí
This structure can also be used when the object in a sentence is a person.
Examples
我们等你等了半个小时
We've been waiting for you for half an hour
wǒmen děng nǐ děng le bàn ge xiǎoshí
If the action started in the past and is continuing into the present
If the action started in the past and is continuing into the present, 了 is placed either one time at the end of a sentence; or twice — one time after the verb and one time at the end of a sentence.
Scheme
verb
(了)
complement
object
了
Examples
我学五年汉语了
I have already been learning Chinese for five years
wǒ xué wǔ nián hànyǔ le
我看了一个小时书了
I've already been reading the book for one hour
wǒ kàn le yí ge xiǎoshí shū le
他们游了半个小时泳了
They have already been swimming for one hour
tāmen yóu le bàn ge xiǎoshí yǒng le
The time-measure complement can also be placed after the object. In this case, only use the particle 了 at the end of a sentence.
Pay attention
The adverb 已经 is often used in this kind of sentence.
is often used in this kind of sentence.Scheme
verb
object
(已经)
complement
了
Examples
她游泳三个小时了
She has been swimming for three hours
tā yóuyǒng sān ge xiǎoshí le
她学芭蕾舞已经五年了
She has already been studying ballet for five years
tā xué bālĕiwŭ yĭjīng wŭ nián le
Pay attention
In this case, the predicate cannot be doubled.