The passive voice is sometimes used in English as well. In the active voice, the subject performs the action on something else; in the passive voice, the action is performed on the subject.
ACTIVE –The doctor wrote a prescription.
PASSIVE –The prescription was written by the doctor.
NOTE: In the passive, the object of the active verb becomes the subject.
To make the passive, use the appropriate form of the verb to be+ past participle. Only transitive verbs are used in the passive:
–Fred helps Jane.
—Jane is helped by Fred.
–He is helping her.
—She is being helped by him.
–He has helped her.
—She has been helped by him.
–He helped her.
—She was helped by him.
–He was helping her.
—She was being helped by him.
–He had helped her.
–She had been helped by him.
–He will help her.
—She will be helped by him.
–He is going to help her.
—She is going to be helped by him.
Usually the by phrase is omitted in a passive sentence. The passive is used mainly when it is not known or not important to know who was responsible for the action: –The house was built in 1960.
(The by phrase is left out because it is understood that builders built the house).