The document discusses the simple past tense. It explains that regular verbs are made past tense by adding "-ed" or "-d", while irregular verbs have unique past forms that must be memorized. It provides examples of forming affirmative, negative, and interrogative sentences in the simple past for both regular and irregular verbs. It also lists common uses of the simple past tense, such as talking about specific past times or events, actions over a period in the past, and habitual past actions.