This document discusses simple past tenses in English. It defines simple past tense as the tense used to express actions that occurred in the past and whose timing is known. There are two types of past tense verbs: regular verbs that are formed by adding "-ed" and irregular verbs that change form. Examples of regular verbs are walked, studied, cried, lived and examples of irregular verbs are taught, gave, became, did. The document also provides formulas for forming positive, negative and interrogative sentences in the simple past tense and gives an example story using past tense verbs.