Stem-changing verbs are the verbs which undergo a complete or partial change in the spelling of the stem, or raíz,
of their infinitive form when conjugated. Verbs ir and ser undergo a complete spelling change in the stem of their
infinitive; verbs hacer and tener undergo a partial spelling change.
Notice that verbs ir and ser have the exact same conjugation in the preterit. To tell them apart, pay attention to the context. Ir (See "Verbal Periph
| IR/SER | ||
| yo | fui | |
| tú | fuiste | |
| él, ella, Ud | fue | |
| nosotros/as | fuimos | |
| vosotros/as | fuisteis | |
| ellos, ellas, Uds | fueron |
Notice that verbs ir and ser have the exact same conjugation in the preterit. To tell them apart, pay attention to the context. Ir (See "Verbal Periph