The document discusses how to write sentences in the past tense. It explains that the simple past tense is used to describe actions that were completed in the past, such as yesterday, last week, last year, etc. For regular verbs, the simple past is formed by adding "-ed" to the base form of the verb. Some irregular verbs like "be" also have unique past tense forms - "was" and "were". Questions in the past tense are formed using "did" plus the subject and base form of the main verb, such as "Did you dance yesterday?".