There are two kinds of changes that can affect stem vowels of some Spanish verbs: diphthongization and vowel raising. Both changes affect -e- or -o- in the last (or only) syllable of a ver… 展开

Cambio vs. envío
Diphthongs in the infinitive may be preserved throughout the c… 展开

Endings starting with o/a in er/ir verbs
In er and ir verbs, the first person singular of the present indicative and the whole present subjunctive are the only forms whose endings s… 展开

The verbs ser (to be) and ir (to go) both exhibit irregularities in the present, imperfect and preterite forms (note that these two verbs have the same preterite fui). Together wit… 展开