Voice is the form of the verb which shows whether the subject acts or is acted on.
A verb is said to be in the active voice when the subject of the verb acts or is the doer of the action. E.g. Moses kills a snake.
A verb is said to be in the passive voice when the subject of the verb is acted on or is the receiver of the action done. E.g. A snake is killed by Moses
When changing from the active voice to the passive voice, note that:
The object of the verb in the active verb becomes the subject of the verb in the passive voice.
The subject of the verb in the active voice becomes the object of the verb in the passive voice and it is generally preceded by the preposition ‘by’
The pronouns ‘I’, ‘we’, ‘he’, and ‘she’ change to ‘me’, ‘us’, ‘him’, and ‘her’ respectively.
The helping verb is in the same tense. number, and person
The principal verb is changed into perfect tense
For example:
Active Voice: I am writing a letter
Passive Voice: A letter is being written by me
When changing from passive voice to the active voice, note:
The object becomes the subject
The pronouns ‘me’, ‘us’, ‘him’, and ‘her’ change to ‘I’, ‘we’, ‘he’, and ‘she’ respectively.