The document provides examples and explanations for using past tense verbs to talk about habits and states that have changed over time. It gives sample sentences using "used to" to discuss past habits and states that no longer exist, such as "I used to live in Saskatoon" or "I didn't use to get along with my sisters." It also advises not using "used to" when stating a specific length of time, like "I lived in Toronto for five years." The document provides questions using "did...use to" and encourages asking follow-up questions. It then shifts to discussing language for reaching agreement and giving opinions.