The document discusses the passive voice in English grammar across three tenses: simple present, future, and past simple. It provides examples of sentences using the passive voice, such as "He opens the door" in the present, "Millions of people will visit the museum" in the future, and "A thief stole my car" in the past simple tense. Across the tenses, the examples demonstrate how the subject receives the action in passive voice constructions compared to active voice.