The prepositions 为 and 为了
We use 为了 to express the purpose of an action. However with 为 we can express who or what the action is for.
The preposition 为
为 
indicates that someone does something for someone or something else. 为 is placed after a subject and before an object.
indicates that someone does something for someone or something else. 为 is placed after a subject and before an object.
Scheme
subject
为
object
who for? what for?
predicate
Examples
我为你付钱
I'll pay for you
wǒ wèi nǐ fùqián
他们为成年人准备了酒，为孩子们准备了汽水
They had wine for adults and soft drinks for children
tāmen wéi chéngnián rén zhǔnbèi le jiǔ, wèi háizimen zhǔnbèi le qìshuǐ
这位勇士为祖国献出了生命
This warrior gave his life for his country
zhè wèi yǒngshì wéi zǔguó xiànchū le shēngmìng
The meaning of 为 is similar to the meaning of 给 , but 给 is more informal than 为.
为 is most often used when referring to obligations or duties. For example, 为 is used when you want to say that a person works for a company.
给 indicates that a matter is voluntary or a person wants to do a favour.
, but 给 is more informal than 为.
为 is most often used when referring to obligations or duties. For example, 为 is used when you want to say that a person works for a company.
给 indicates that a matter is voluntary or a person wants to do a favour. Pay attention
We mostly use 为 in formal speech.
Examples
他为卫生部工作
He works for the Ministry of Health
tā wéi wèishēngbù gōngzuò
我很乐意为你工作
I'd be happy to work for you
wǒ hěn lèyì wèi nǐ gōngzuò
为 also means "because of", "for the purpose of".
Examples
我为这事担心
I'm worried about this
wǒ wèi zhè shì dānxīn
他为婚姻破裂而沮丧
He was disappointed by the breakdown of his marriage
tā wéi hūnyīn pòliè ér jǔsàng
The preposition 为了
The preposition 为了 describes the purpose of an action.
It can be followed by words denoting a person or an inanimate object. For example: for your sake, for money.
It can also be followed by words denoting an abstract concept or an action. For example: for your safety, in order to buy a house.
describes the purpose of an action.
It can be followed by words denoting a person or an inanimate object. For example: for your sake, for money.
It can also be followed by words denoting an abstract concept or an action. For example: for your safety, in order to buy a house.Scheme
为了
target
for what? for what?
an action
Examples
为了钱，他卖了自己的手表
He sold his watch in order to get some money
wèile qián, tā mài le zìjǐ de shǒubiǎo
为了安全，门总是关着的
The door is always closed for safety reasons
wèile ānquán, mén zǒngshì guānzhe de
We can state the subject either at the beginning or in the middle of the sentence.
If we state the subject in the middle of a sentence, as in the examples above, we should put a comma before it.
If the subject is stated at the beginning of the sentence, we should put the conjunctions 而 or 才 between the target and the action.
or 才 between the target and the action.Examples
她为了玩而活着
She believes life is all about having fun
tā wèile wán ér huózhe
我为了转机才在北京停留
My connecting flight is in Beijing
wǒ wèile zhuǎnjī cái zài běijīng tíngliú
We also can state the target at the end of the sentence. In this case we should use the verb 是 before 为了.
before 为了.Scheme
an action
是为了
target
for what?
Pay attention
With both 为了 and为, we can state a person as the target. In this case they have the same meaning “for someone's sake”.
Examples
我这么做是为了你
I did it for you
wǒ zhème zuò shì wèile nǐ
我所做的一切都是为了你
I did this all for you
wǒ suǒ zuò de yīqiè dōu shì wèile nǐ
Pay attention
In such sentences, the focus shifts to the target itself.