The document summarizes the uses of different past tenses in English, including the simple past, past progressive, past perfect, and past perfect progressive. The simple past is used to denote completed past events or habitual past actions. The past progressive emphasizes ongoing or repeated past actions and can denote future plans in the past. The past perfect focuses on actions completed before a point in the past. Finally, the past perfect progressive combines the ideas of the past perfect and past progressive to refer to ongoing actions completed by a time in the past.