被字句
RulePatient + bei + (agent) + verb + extra: passive, "to be V-ed".
Curiosity
How do you make the one affected the subject, as in "I was praised by the teacher"?
Intuition
被 (bei) puts the affected one (patient) first and the agent after bei. If ba takes the doer's viewpoint, bei takes the receiver's: they mirror each other.
Visualization
From active [teacher][praised][me], move the patient me to the front: [me][bei][teacher][praised].
Active (agent as subject)
老师agent表扬了verb我patient
被 construction (patient as subject)
我patient被被 (passive)老师agent表扬了verb
Essence
The agent after bei can be omitted (wo bei piping le). Like ba sentences, the verb usually carries a result or le. Useful when the agent is unknown or left out.
Examples
我被老师表扬了。
I was praised by the teacher.
杯子被打破了。
The cup was broken.
蛋糕被弟弟吃了。
The cake was eaten by my little brother.
Mini-quiz
Which bei sentence means "my bike was stolen"?