This document discusses irregular verbs in English and provides examples of common irregular verbs and their past tense forms. It lists 20 irregular verbs such as "buy" and "bought", "teach" and "taught", and "drink" and "drank". It explains that irregular verbs form their past tense not by adding "-ed" or "-d" but by changing the vowel or consonant within the word. At the end it directs the reader to complete an assignment to memorize 10 irregular verb pairs.