Voice is that form of a verb which shows whether the subject does something or has something done to it. There are two voices in the English language: Active voice and Passive voice.

Active voice

A verb is in the active voice when its subject does something.

1. Khurshid (subject) helps Naushaba (object)
2. The driver (subject) opened the door of the car (object)
3. The boy (subject) makes the picture (object)

Passive voice

A verb is in the passive voice when something is done to its subject

1. Naushaba is helped by Khurshid
2. The door of the car was opened by the driver
3. The picture is made by the boy

We see that the following changes take place when a sentence is changed from the active to passive voice

1. The subject becomes the object and the object becomes the subject
2. The principal verb is changed into the past participle (if it is not already in that form) and is preceded by some form of the verb be
3. The preposition by is placed before the object

Following is a list of sentences – (in various tenses) changed from the active into the passive voice

1. The mother loves the children

The children are loved by the mother (present indefinite tense)

2. they are buying this house

This house is being bought by them (present continuous)

3. she has not beaten the dog

The dog has not been beaten by her (present perfect)

4. she bought five video films

Five video films were bought by her (present perfect)

5. She gave me five films

I was given five films by her

6. She was teaching the students

The students were being taught by her (past continuous)

7. They had gained nothing

Nothing had been gained by them (past perfect)

8. he will write a letter

A letter will be written by him (future indefinite)

9. We shall have killed the snake

The snake will have been killed by us (future perfect)

Note: sentences in the present perfect continuous, past perfect continuous, and future perfect continuous are not changed into the passive voice.