That definition of passive voice is extremely general and abstract because it's meant to apply to all human languages. The Wikipedia definition of English pass

That definition of passive voice is extremely general and abstract because it's meant to apply to all human languages. The Wikipedia definition of English passive voice is more instructive: https://en.wikipedia.org/wiki/English_passive_voice https://en.wikipedia.org/wiki/English_passive_voice . The term distinguishes between sentences where the semantic agent is the syntactic subject, and those where it is the object. For example: "Bob threw a ball at Suzie" (active, Bob is the syntactic subject) vs. "A ball was thrown at Suzie by Bob" (passive, Bob is the object of a preposition and "a ball" is the subject).