Spanish Grammar Guide

Spanish stem-changing verbs

In the present tense, some verbs have a stem change: a letter in its root changes in some of the grammatical persons. There are two types of stem changes:

E changes to IE

Pensar (to think)
Yo pienso
Tú piensas
Él/Ella/Ud. piensa
Nosotros/as pensamos
[Vosotros/as pensáis]
Ellos/Ellas/Uds. piensan

This happens in many verbs; it doesn’t matter if they are -AR, -ER or -IR. Note that the e changes to ie in all persons except Nosotros and Vosotros.

Here are some common “e to ie” verbs:

Cerrar - to close
Divertirse - to have fun
Empezar* - to start/to begin
Entender - to understand
Mentir - to lie
Pensar - to think
Perder - to lose
Preferir - to prefer
Querer - to want/to love
Recomendar - to recommend
Sentarse - to sit down
Sentirse - to feel

* Note: the stem change always happens in the strong syllable: empiezo, entiendo, prefiero.

O changes to UE

Soñar (to dream)
Yo sueño
Tú sueñas
Él/Ella/Ud. sueña
Nosotros/as soñamos
[Vosotros/as soñáis]
Ellos/Ellas/Uds. sueñan

Again, the o changes to ue in all persons except Nosotros and Vosotros.

Here are some common “o to ue” verbs:

Acostarse - to go to bed/to lie down
Almorzar - to have lunch
Contar - to tell/to count
Costar - to cost
Devolver - to return (an item)
Dormir - to sleep
Dormirse - to fall asleep
Encontrar - to find
Mover - to move (an item)
Morir - to die
Poder - to be able to
Recordar - to remember
Sonar - to sound
Soñar - to dream
Volar - to fly
Volver - to return

Also, the verb jugar (to play, for sports or games) is conjugated this way: yo juego, tú juegas, etc.

Verbs with stem change in the past tense (pretérito perfecto)

Stem-changing verbs do not change their stem in the past tense:

Pensar (to think)
Yo pensé
Tú pensaste
Él/Ella/Ud. pensó
Nosotros/as pensamos
[Vosotros/as pensasteis]
Ellos/Ellas/Uds. pensaron
Soñar (to dream)
Yo soñé
Tú soñaste
Él/Ella/Ud. soñó
Nosotros/as soñamos
[Vosotros/as soñasteis]
Ellos/Ellas/Uds. soñaron

NOTE: Verbs divertirse, mentir, morir, preferir, querer, sentirse, dormir and poder are irregular in the pretérito perfecto tense.

Berges Institute logo

Join thousands of students who are already learning Spanish with us!

Unlimited live classes + Full access to video library.
FREE for the first 15 days. Trial starts on the day of your first class.
/month after your free trial. 89% decide to stay with us.
Cancel directly on the website, before your trial ends, or any time after.