The document discusses the simple past tense in English. It explains that there are two types of verbs in the past tense: regular verbs which take "-ed" and irregular verbs which have varying forms. Regular verbs follow patterns like doubling consonants or just adding "-d" depending on their spelling. Irregular verbs have unpredictable changes and need to be memorized. Examples of negative and yes/no question forms are also provided, using "did/didn't" with regular verbs and "was/were" with the verb "to be".