Rules for changing voice:

Rule 1: The subject and the object get interchanged
Examples: My brother bought a new car..
                A new car was bought by my brother.

Here, the object ‘A new car’ is the subject in the passive voice.

Rule 2: By gets added to the agent(object) in passive voice.

Example: Superb dinner was prepared by chef.

Rule 3: The verb changes to its third form or past participle form in the passive voice.

Example: English is spoken all over the world.

Rule 4: The new auxiliary form is added before the third form or past participle form in the
            passive voice.

• For the simple present tense use am, is or are with a past participle to form the
• For the simple past tense, use was or were with a past participle to form the
• For the present continuous tense, use am, is or are with “being” followed by a past participle, to form the passive voice.
• For the past continuous tense, use was or were with being, followed by a past participle, to form the passive voice.
• For the future tense, use shall or will with be, followed by a past participle, to form the passive voice.
• For the present perfect tense, use have or has with been, followed by a past participle, to form the passive voice.
• For the past tense, use had with been, followed by a part participle, to form the passive voice.