Some -ir verbs behave like regular verbs in most forms of the preterite but change their stem in the third-person singular and third-person plural. If the stem vowel is e, it becomes i in those two forms only. The yo, tú, and nosotros forms stay regular.
Which Verbs Do This?
Only -ir verbs that stem-change in the present (e → ie or e → i) show this preterite pattern. -ar and -er verbs never do, even if they stem-change in the present (pensar, entender, and perder are all perfectly regular in the preterite).
The Pattern with pedir
| Subject | pedir |
|---|---|
| yo | pedí |
| tú | pediste |
| él / ella / usted | pidió |
| nosotros / nosotras | pedimos |
| ellos / ellas / ustedes | pidieron |
The stem vowel is e in pedí, pediste, pedimos but i in pidió, pidieron. The endings themselves are still the standard -er/-ir preterite endings.
Yo pedí una ensalada.
I ordered a salad.
Él pidió una pizza.
He ordered a pizza.
Ellos pidieron dos postres.
They ordered two desserts.
Another Example: sentir
Sentir (to feel) has an e → ie change in the present but an e → i change in the preterite third-person forms.
| Subject | sentir |
|---|---|
| yo | sentí |
| tú | sentiste |
| él / ella / usted | sintió |
| nosotros / nosotras | sentimos |
| ellos / ellas / ustedes | sintieron |
Ella sintió un gran alivio.
She felt a great relief.
Los atletas sintieron el cansancio.
The athletes felt the tiredness.
Common E → I Verbs
All of the following -ir verbs show the e → i shift in the third-person preterite. The yo, tú, and nosotros forms stay regular.
| Infinitive | Meaning | 3rd sg. | 3rd pl. |
|---|---|---|---|
| pedir | to ask for | pidió | pidieron |
| servir | to serve | sirvió | sirvieron |
| repetir | to repeat | repitió | repitieron |
| seguir | to follow | siguió | siguieron |
| vestir(se) | to dress | vistió | vistieron |
| preferir | to prefer | prefirió | prefirieron |
| mentir | to lie | mintió | mintieron |
| sentir | to feel | sintió | sintieron |
| reír | to laugh | rió | rieron |
El mesero sirvió el vino.
The waiter served the wine.
A Note on reír
Reír and sonreír drop an i: rió and rieron, sonrió and sonrieron (not *riió). Modern spelling no longer writes the accent on rio, rieron, but older texts may show rió.
Todos rieron con el chiste.
Everybody laughed at the joke.
What Stays Regular
Do not overapply this rule. The first and second person forms (yo, tú, nosotros) are fully regular:
- pedí — not *pidí
- pediste — not *pidiste
- pedimos — not *pidimos
Only the two third-person forms take the stem change. Keep that scope in mind and you will not overcorrect.
Common mistakes
❌ Yo pidí una ensalada.
Wrong: the stem change only happens in the third person.
✅ Yo pedí una ensalada.
Correct: the yo form keeps the original e.
❌ Él pedió una pizza.
Wrong: the third-person form must change e → i.
✅ Él pidió una pizza.
Correct: pidió with the stem change in the third person.
❌ Nosotros pidimos la cuenta.
Wrong: nosotros does not stem-change in the preterite.
✅ Nosotros pedimos la cuenta.
Correct: pedimos keeps the original e.
❌ La profesora repitió... los estudiantes repitieron... yo repití.
Wrong: applying the stem change to the yo form.
✅ Yo repetí, ella repitió, ellos repitieron.
Correct: stem change only in él/ella and ellos/ellas.
Related Topics
- Regular -er and -ir VerbsA2 — Regular -er and -ir verbs share one set of preterite endings: -í, -iste, -ió, -imos, -ieron.
- Stem Change: O to UB1 — The -ir verbs dormir and morir shift o to u in the third-person preterite forms: durmió, murieron.
- Irregular GerundsA2 — Stem-changing -ir verbs and verbs with a vowel before the ending form special gerunds like durmiendo, pidiendo, and leyendo.