Three of the irregular preterite tense verbs that you've learned so far - hacer, saber, and estar - use these endings. Do you remember how to conjugate these verbs? hacer saber estar hic'e' sup'e' estuv'e' hic'iste' sup'iste' estuv'iste' hiz'o' sup'o' estuv'o' hic'imos'...