Passive voice(1 object)

In the active voice, the subject of the sentence DOES the action:

Shela washes the dishes. 

Subject / verb / object

In the passive voice, the subject of the sentence is acted upon:  The dishes are washed (by John).  Subject / verb Notice that the object of the active sentence (book) became the subject of the passive sentence.  Note: we use the past participle form of a verb in constructing a passive voice sentence and question. 

PASSIVE VERB TENSES

PRESENT SIMPLE

ACTIVE VOICE: She eats an apple.

PASSIVE VOICE: The apple is eaten.

PAST SIMPLE

ACTIVE VOICE: She ate an apple.

PASSIVE VOICE: The apple was eaten. 

FUTURE SIMPLE

ACTIVE VOICE: She will eat an apple.

PASSIVE VOICE: The apple will be eaten. 

PRESENT CONTINUOUS

ACTIVE VOICE: She is eating an apple.

PASSIVE VOICE: The apple is being eaten. 

PAST CONTINUOUS

ACTIVE VOICE: She was eating an apple.

PASSIVE VOICE: The apple was being eaten.

PRESENT PERFECT

ACTIVE VOICE: She has eaten an apple.

PASSIVE VOICE: The apple has been eaten.

PAST PERFECT

ACTIVE VOICE: She had eaten an apple.

PASSIVE VOICE: The apple had been eaten.

MODALS

ACTIVE VOICE: She must eat an apple.

PASSIVE VOICE: The apple must be eaten. 

USE:

The Passive is used: 

When the agent (= the doer of the action) is unknown, unimportant or obvious from the context. 

For Example,

The Prime Minister was shot. 

This church was built in 1950. 

The criminals have been arrested. 

To make more polite or formal statements. 

For Example,

The room hasn’t been cleaned yet. 

The questions weren’t answered. 

When the action is more important than the agent, as in processes, instructions, events, reports, headlines, new items, and advertisements.

For Example,

30 people were killed in the earthquake. 

10 people have been rushed to the nearest hospital. 

To put emphasis on the agent

For Example,

The new library will be opened by the Mayor. 

We were taught English by a senior professor.