The document discusses the simple past tense in English. It explains that the simple past is used to talk about actions that were completed in the past. It provides examples of regular and irregular verbs in the simple past, such as "play/played" and "go/went". It also discusses how the auxiliary verb "do" changes to "did" in the past tense. The document provides examples of simple past sentences, negative sentences, and question forms to illustrate its usage.