The document discusses the simple past tense in English. It notes there are two types of past tense verbs: regular and irregular. Regular verbs form the past tense by adding "-ed" to the base verb, with some consonant and vowel changes. Irregular verbs have unpredictable spelling changes to form the past tense and must be memorized. Examples of both regular and irregular past tense verbs are provided. The purpose and formation rules of regular past tense verbs are explained in detail.