The document discusses using the passive voice in writing. It defines active and passive voice and provides examples of changing sentences from active to passive voice. Some key points include: passive voice takes the form of "B is done (by A)" while active voice is "A does B"; the passive voice omits the agent of the action and changes the verb to a form of "to be" plus the past participle. The document also demonstrates how to properly change verb tense and number when changing between active and passive voice.