-ir stem-changing verbs in the Preterite

-ar and –er verbs that have a stem change in the Present tense do not have a corresponding change in the Preterite. However, -ir shoe verbs do have a stem change in the Preterite tense. Unlike in the Present tense, they do not change in the “shoe”, they change only in the 3rd persons (he, she, you (Ud), they and you (Uds) forms. Present tense o>ue changes become o>u in the preterite. Present tense e>ie and e>i changes become e>i in the Preterite.

Dormir (ue, u)

Present Preterite

Duermo dormimos dormí dormimosDuermes dormís dormiste dormisteisDuerme duermen durmió durmieron

Sentir (ie, i)

Present Preterite

Siento sentimos sentí sentimosSientes sentís sentiste sentisteisSiente sienten sintió sintieron

Pedir (i, i)

Present Preterite

Pido pedimos pedí pedimosPides pedís pediste pedisteisPide piden pidió pidieron