Stem-changing verbs (e→ie, o→ue, e→i) explained
By Tarek Sahyoun ·
Stem-changing verbs use regular endings, but the vowel in the stem changes when it carries the stress. There are three kinds.
| Change | Example | yo | nosotros |
|---|---|---|---|
| e → ie | pensar | pienso | pensamos |
| o → ue | dormir | duermo | dormimos |
| u → ue | jugar | juego | jugamos |
| e → i | pedir | pido | pedimos |
Ever said jugo al fútbol and got a funny look? That was me. Jugo is juice. Juego is "I play". That one vowel is the whole lesson of this post.
e → ie
Pensar, querer, empezar, entender, sentir.
Pienso en ti.I'm thinking about you.
¿Quieres café?Do you want coffee?
La clase empieza a las nueve.Class starts at nine.
o → ue
Poder, dormir, volver, encontrar, contar. Jugar is the one u → ue verb: juego, juegas.
No puedo ir.I can't go.
Duermo ocho horas.I sleep eight hours.
Vuelven mañana.They're coming back tomorrow.
e → i (only -ir verbs)
Pedir, servir, repetir, seguir, vestir.
Siempre pido lo mismo.I always order the same thing.
¿Para qué sirve esto?What is this for?
The boot rule
In the present, the change happens in yo, tú, él/ella and ellos, but not in nosotros or vosotros, because there the stress moves to the ending. Written as a table, the changed forms make the shape of a boot: pienso, piensas, piensa, pensamos, pensáis, piensan.
I literally drew the boot on a sticky note and kept it on my laptop for a month. Silly, but it works.
In other tenses
- Present subjunctive: same boot pattern (piense, pueda). Stem-changing -ir verbs also change in nosotros and vosotros: durmamos, pidamos.
- Preterite: -ar and -er verbs don't keep the present-tense e → ie or o → ue changes (pensé, volví), but some have other irregular stems (pude, quise). Verbs such as pedir and dormir change e → i and o → u in the third person only: pidió, pidieron, durmió, durmieron.
- Gerund: -ir verbs change too: pidiendo, durmiendo.
How to spot one
You can't tell from the infinitive alone: comer doesn't change but volver does. Learn the common ones as you meet them; the verb list lets you filter for stem-changing verbs.
Common verbs in each group
- e → ie: cerrar, comenzar, empezar, entender, perder, preferir, querer, sentir, despertar(se).
- o → ue: almorzar, contar, costar, dormir, encontrar, morir, mostrar, poder, recordar, volver.
- e → i: competir, despedir, elegir, medir, pedir, reír, repetir, seguir, servir, vestir(se).
Full present tables
| querer | volver | servir | |
|---|---|---|---|
| yo | quiero | vuelvo | sirvo |
| tú | quieres | vuelves | sirves |
| él | quiere | vuelve | sirve |
| nosotros | queremos | volvemos | servimos |
| vosotros | queréis | volvéis | servís |
| ellos | quieren | vuelven | sirven |
Spelling changes on top
Some verbs combine a stem change with a spelling change. Empezar and almorzar change z to c before e (empiece, almuerce). Seguir drops the u before o (sigo). Elegir changes g to j (elijo). Each verb page shows these forms in full.
The preterite: vowel changes and other irregularities
In the preterite, -ar and -er verbs don't keep their present-tense e → ie or o → ue changes: pensé, volví. That doesn't make every verb regular: poder and querer have the irregular forms pude and quise. Verbs such as pedir and dormir change e → i or o → u in the third person, singular and plural only: pidió, durmieron.
Ella pidió la cuenta.She asked for the bill.
Los niños durmieron toda la noche.The children slept all night.
Pensé en ti.I thought about you.
The gerund
Stem-changing -ir verbs also change in the gerund: durmiendo, pidiendo, sirviendo, sintiendo. "El bebé está durmiendo" (the baby is sleeping) is a phrase you'll hear constantly.
Common mistakes
Nosotros piensamos.→ Nosotros pensamos.No stem change in nosotros: the stress falls on the ending.
Yo jugo al tenis.→ Yo juego al tenis.Jugar changes u to ue.
Ella pedió agua.→ Ella pidió agua.Stem-changing -ir verbs change e to i in the third-person preterite.
Yo volví a casa y duermí.→ Yo volví a casa y dormí.In the preterite, dormir only changes in él/ella and ellos.
Yo sego las instrucciones.→ Yo sigo las instrucciones.Seguir is an e→i verb and drops the u before o.
More examples
¿Cuánto cuesta?How much does it cost?
No entiendo la pregunta.I don't understand the question.
Prefiero el té.I prefer tea.
Siempre pierdo las llaves.I always lose my keys.
¿Me repites el número?Can you repeat the number for me?
Test yourself
- Yo ___ (poder) ayudarte.
Show answer
puedo - Nosotros ___ (querer) ir al cine.
Show answer
queremos: no change in nosotros. - ¿A qué hora ___ (empezar) la película?
Show answer
empieza - Ellos ___ (pedir) una pizza. (preterite)
Show answer
pidieron - Ella ___ (dormir) poco. (present)
Show answer
duerme - Vosotros ___ (dormir) mucho.
Show answer
dormís: no change in vosotros. - El camarero nos ___ (servir) la comida. (preterite)
Show answer
sirvió - Yo no ___ (recordar) su nombre.
Show answer
recuerdo
Keep going
Verb tables: pensar, querer, empezar, poder, dormir, volver, jugar, pedir, servir
Tense lessons: Present, Present subjunctive, Preterite
Practice the present