Passive Voice

FORM

BE + PAST PARTICIPLE

This house was built in 1486.

The roof is being repaired by a friend of ours.

They built this house in 1486. ➡️ This house was built in 1486.

A friend of ours is repairing the roof. ➡️ The roof is being repaired by a friend of ours.

USE

The passive is used to focus attention on the action or the person or thing affected by the action.

If the agent is mentioned, the preposition by is used:

I was shocked by your attitude.

The agent is not usually mentioned in passive constructions if it is...

1. unknown: My car has been stolen.

2. unimportant: My car has been repaired.

3. obvious: The criminal has been arrested.

4. 'people in general': That road hasn't been used for years.

VERBS WITH TWO OBJECTS

verb + indirect object + direct object

I had given Peter a present. 

Peter had been given a present.

verb + direct object + indirect object

I had given a present to Peter.

A present had been given to Peter.

HAVE + OBJECT + PAST PARTICIPLE

It can be used to show that the subject arranges for the action to be done by someone else.

I'll have my hair cut.

Get is a more informal alternative.

I'll get my hair cut.

FURTHER PASSIVE CONSTRUCTIONS

The infinitive or perfect infinitive with to can be used with certain verbs to give generalized opinions or facts. Verbs used in this way include: allege, believe, consider, estimate, expect, know, report, say, think, understand, as well as be rumored and be reputed.

People believe that he crossed the frontier last night.

It is believed that he crossed the frontier last night.

He is believed to have crossed the frontier last night.