为...所 wéi... suǒ [passive structure] Origin Definitions Defs Strokes Stroke Words Sentences Sents 为 為 wéi preposition [passive] Used to introduce the person or thing performing an action, meaning "by"; often used in the 为...所 wéi... suǒ pattern.所 suǒ particle [passive] Used in the 为...所 wéi... suǒ pattern to indicate the passive voice, showing that someone or something is being acted upon.