For Prep. 为

The usage of为(wèi)
为(wèi) here is used as a preposition to mean “for” someone or something, and the preposition phrase is always followed by a verb phrase.

Sentence pattern:

(一), Subj. +为(wèi) + NP + VP

Examples: 1, David is working for an American company.
大(dà) 卫(wèi) 为(wéi) 一(yī) 家(jiā) 美(měi) 国(guó) 公(gōng) 司(sī) 工(gōng) 作(zuò) 。

2, The manager of the Chinese company has prepared Chinese food for t he American guests.
中(zhōng) 方(fāng) 经(jīng) 理(lǐ) 为(wéi) 美(měi) 国(guó) 客(kè) 人(rén) 准(zhǔn) 备(bèi) 了(le) 中(zhōng) 餐(cān) 。

为(wèi) can also mean “for the purpose of” or “for the sake of”. In this case, 而(ér) can be added in between the preposition phrase and the verb / adjectival phrase.

(二). Subj. + 为(wèi) + NP +而(ér) + VP / AP

Examples:
1, I am glad that we have a cooperation plan.
我(wǒ) 为(wèi) 我(wǒ) 们(men) 的(de) 合(hé) 作(zuò) 计(jì) 划(huà) 而(ér) 高(gāo) 兴(xìng) 。

2, Mary is learning Chinese for the sake of doing business in China.
玛(mǎ) 丽(lì) 为(wéi) 在(zài) 中(zhōng) 国(guó) 做(zuò) 生(shēng) 意(yì) 而(ér) 学(xué) 习(xí) 中(zhōng) 文(wén) 。

The structure of 为(wèi) + NP + VP sometimes can be used as a modifier followed by的(de) to modify a noun phrase.

Example:
Miss Li who works for our company is coming.
为(wèi) 我(wǒ) 们(men) 公(gōng) 司(sī) 工(gōng) 作(zuò) 的(de) 李(lǐ) 小(xiǎo) 姐(jiě) 来(lái) 了(le) 。