The document discusses the passive voice and how it differs from the active voice. The passive voice focuses on the object of the sentence and what is happening to it, rather than the subject or doer of the action. It provides examples of converting sentences from active to passive voice by using forms of the verb "to be" plus the past participle of the main verb. Various tenses that can be used in the passive voice, such as simple present, simple past, present continuous, and present perfect, are also outlined along with their structures.