The preterite is one of the two main past tenses used in Spanish. In fact of the two past tenses (the imperfect tense being the other one!) it is probably used the most.Unfortunately, in Spanish, if a specific verb or tense is used a great deal, it is usually the case that there are a great number of irregularities to be learned. The only good thing about this is that the most difficult parts of verb use are practiced daily.In order to learn irregular verbs in the Spanish preterite one must know the regular f employment laws uk ormation of this tense. As you are no doubt aware there are three groups of verbs in Spanish, the -er, -ar and -ir verb groups.Each of these three verb groups usually has specific endings for each separate tense, although the -er and -ir verb groups often share the same endings depending upon which tense is being used…the preterite is one tense in particular when this is the case.Regular Verb Endings in the Spanish PreteritHere are the regular endings (in bold) for each group of verbs in the preterite tense.