Rule 4. Change the base verb in the active sentence into the past participle ie. third form verb in a passive sentence i.e. preceded by (By, With, to, etc). Base verbs are never used in passive voice sentences.
Example: Active voice: She prepares dinner. / Passive voice: The dinner is prepared by her.

Rule 5. While conversion of Active voice sentence to Passive voice sentence, the pronoun used in the sentence also changes in the following manner.
Example: I / Me ; We / Us ; He / Him; She / Her; They / Them

Rule 6. Use the suitable helping or auxiliary verb (is/am/are/was, etc.). The rules for using auxiliary verbs in passive voice sentences are different for each tense.
Example: He writes an essay - An essay is written by him / Ria paid the bills - The bills were paid by Ria / He will write a letter - A letter will be written by him