This document discusses the active and passive voice in English. It defines the active voice as using an active verb to describe what the subject does to the object, while the passive voice uses a passive verb to describe what happens to the subject, with the object becoming the subject. It provides examples of sentences in both voices and discusses when to use the passive voice, such as when the agent is unknown, unimportant, or obvious from context. It also covers types of passive forms like modal passives and exceptions to using the passive voice.