Introduction: Voice is the form of the verb which shows whether the subject acts or is acted upon.
Consider the following sentences:
(i) Raja loves Reena.
(ii) Reena is loved by Raja.
There is practically no difference in the meanings of the above two sentences. These are two different ways of presenting the same thing. But in the first sentence, the subject performs the action, whereas in the second sentence, The subject of the verb is acted upon. It means the subject of the first sentence becomes the object of the verb of the first sentence.
The voice shows whether subject performs the action or the subject receives the action.
Kinds of Voice
There are two voices:
(i) Active voice
(ii) Passive voice
When the subject of the sentence is the doer or actor, the verb is active and said to be in Active Voice.
(i) He runs.
(ii) I did it.
(iii) She helped me.
(iv) They did all the work.
When the subject of the sentence is acted upon, the verb is passive and is said to be in Passive Voice.
(i) It was done by me.
(ii) This was said by him.
(iii) The thief was arrested.
(iv) The sun was covered by cloud.
Rules for changing the voice
1. The object of the active voice is changed into subject of the passive voice.
2. The subject of the active voice is changed into object of the passive voice.
3. According to the subject made in the passive voice, there is the usage of the helping verb.
If it is not the helping verb 'to be', then according to the helping verb present there, a form of 'to be' is taken into usage.
4. After 'to be' there is the usage of v3.
5. Preposition 'by' is used before the object made in the passive.
This (by + object) is also known as (by + agent), which is completely optional.
6. The tense of the verb is not changed. Only its form is changed, i.e. tense of the verb remains the same.
7. Vague subjects, like someone, somebody, everybody, everyone, people, etc. are dropped in the form of a passive voice.