The document discusses the formation of sentences in the simple past tense in English. It states that for affirmative sentences, the base form of the verb is used for both regular and irregular verbs. For negative sentences, "did not" or "didn't" is used along with the infinitive verb form. For questions, "did" is used along with the infinitive verb form. Examples are provided to illustrate simple past tense sentence formation for the first, second and third person singular and plural subjects.