The document discusses different past tenses in English - simple past, past continuous, past perfect, and past perfect continuous. It provides definitions and examples of each tense. The simple past is used to talk about completed past actions. The past continuous describes an ongoing action in the past. The past perfect refers to an earlier past time before some other past time mentioned. The past perfect continuous describes an action that had been ongoing up until a past time. Structures and uses of each tense are outlined.