The document discusses the passive voice in English. 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 and is often omitted or mentioned after "by". Examples of active and passive sentences in different tenses are provided. The use of the passive voice in English, such as when the doer is unknown or less important, is also explained.