The document discusses the use of the passive voice in English. It explains that the passive voice is used when the action is more important than the subject performing the action. It provides examples of changing active sentences to passive sentences. The key elements are: 1) making the direct object of the active sentence the subject of the passive sentence, 2) using the appropriate form of "to be" plus the past participle of the main verb, and 3) optionally including "by" plus the original subject. Various tenses and structures of the passive voice are covered.