作 + 为 + Role/Identity
The verb 作 (zuò) means 'to act,' 'to do,' or 'to serve as.' It frequently appears in the compound 作为 (zuòwéi), meaning 'to act as' or 'in the capacity of.' On its own, 作 is more literary and is common in formal or written Chinese.
这部电影是他作的曲。
Zhè bù diànyǐng shì tā zuò de qǔ.
He composed the music for this movie.
不要无病呻吟、故作姿态。
Bù yào wúbìng shēnyín, gùzuò zītài.
Don't moan about imaginary problems or put on airs.
他年轻时曾作过几首诗。
Tā niánqīng shí céng zuò guò jǐ shǒu shī.
He wrote a few poems when he was young.