The document discusses the passive voice in English grammar. It defines the passive voice as forming the verb "to be" in the same tense as the active verb and adding the past participle of the active verb. The subject of the active verb becomes the agent of the passive verb. Various passive verb tenses and their active counterparts are provided in a table. The document also covers uses of the passive voice, forming the passive from active sentences, and other grammatical aspects of the passive voice like agents, double object verbs, and exercises.