Subject(affected) + 被 + (Agent) + Verb + Result/了/Complement

The 被 (bèi) construction — passive voice

被 (bèi) marks the passive voice — the sentence's subject is the one something was DONE TO, not the doer. Structure: affected thing/person + 被 + (optionally, who did it) + verb + an extra element (了, a result complement): 我的钱包被(小偷)偷了 (my wallet was stolen [by a thief]). Like 把, a 被-sentence's verb almost always needs something after it — a bare verb alone feels incomplete. Chinese uses passive voice less often than English, and mainly when something negative or noteworthy happened to the object; many English passive sentences read more naturally in Chinese as plain active sentences or 把-sentences instead. The deciding question: do I need to emphasize that the subject was affected by an action — often something unwanted — rather than describe who did it? If you're just narrating a normal completed action from the doer's side, plain word order or 把 is usually more natural than forcing 被.