Below the basic rules for changing active voice to passive voice is given:

Table of Contents

Rule No. 1

Voice change can only happen when a sentence contains transitive or action verbs. Transitive verbs use direct object to complete the expression. 

Examples

Active VoicePassive Voice
Rabi paints realistic portraits.  Realistic portraits are painted by Rabi. 
Trisha is working on the project.The project is being worked on by Trisha. 

Rule No. 2

The subject and the object of the sentence change places. Subject is replaced by object in passive voice. And subject is placed on the place of object.

Examples

Active VoicePassive Voice
Rupa teaches Maths to children.Maths is taught to children by Rupa
Mother scolded himHe was scolded by mother.  

Rule No. 3

Personal pronouns change while converting a sentence form active to passive voice.

Examples

Active VoicePassive Voice
I gave him the book.The book was given to him by me
He was organizing the programme.The programme was being organized by him
The teacher praised her for her excellent performance.She was praised for her excellent performance by the teacher. 

Rule No. 4

Each tense have their specific rules for changing active voice to passive voice. The main verb of a sentence of all tenses has to be in past participle form in passive voice. 

Examples

Active VoicePassive Voice
Mohan sang a song for us. A song was sung for us by Mohan. 
Priti brought flowers for her. Flowers were brought for her by Priti.  

Rule No. 5

In passive voice a preposition [by/to/with] is placed before the subject. The preposition ‘by’ is most commonly used. 

Examples 

Active VoicePassive Voice
Water flooded the city.The city was flooded with water. 
Moumita baked delicious cake.Delicious cake was baked by Moumita.  
He knows the rules of the game.The rules of the game is known to him.