Subject + 为 + Beneficiary + Verb + Object
The preposition 为 (wèi) means 'for' or 'on behalf of' and introduces the beneficiary of an action. It is placed before the person or group that benefits, forming a prepositional phrase that precedes the main verb, as in 为孩子准备礼物 (prepare gifts for the children).
妈妈为我们准备了一桌好菜。
Māma wèi wǒmen zhǔnbèi le yī zhuō hǎo cài.
Mom prepared a whole table of delicious dishes for us.
他为朋友的生日买了一份礼物。
Tā wèi péngyǒu de shēngrì mǎi le yī fèn lǐwù.
He bought a gift for his friend's birthday.
老师为学生们花了很多时间。
Lǎoshī wèi xuéshēngmen huā le hěn duō shíjiān.
The teacher spent a lot of time for the students.