What is the passive verb in the following sentence?: The car was bought by the man who is speaking with his wife.
"Was bought" is the passive verb.
Passive voice verbs are marked by a form of the verb to be (in this case, "was"). They indicate that the subject of the verb is being acted on, rather than acting.
In this case, was bought indicates that the buying happens to the car, rather than the car buying the man!