The document provides examples of using past tense forms to ask and answer questions, make negative and positive statements. It shows how to express that something did not happen in the past or express regret using the verbs "had" and "would have". Questions are formed using "did" plus the base verb. Negative statements use "didn't" plus the base verb. Positive statements use the past tense form of the verb. Regret can be expressed by saying "if...had...would have...".