The document discusses the passive voice and how to form passive sentences in different tenses, including the present simple, present continuous, past simple, present perfect, past perfect, and future. Examples are provided to illustrate how to transform active sentences into their passive equivalents in each tense by using the appropriate form of "to be" along with the past participle of the main verb. Certain verbs like "die", "happen", and "stay" are noted as being unable to be used in the passive voice.