The document discusses the past simple tense, also known as the past simple. The past simple is used to talk about actions that were completed in the past. It provides examples of regular verbs like "worked" and irregular verbs like "was" in the past simple form. It then gives examples of affirmative sentences using the past simple to describe finished actions like "My brother finished his homework." Negative examples are also provided like "They didn't eat pizza yesterday." Finally, it lists interrogative sentences using the past simple tense to ask questions like "Did Mary eat rice for dinner?"