As you may already know, all verbs in the language are formed by a stem and an ending. Regular verbs only change their ending according to some simple rules without affecting the first part of the verb, but Spanish stem-changing verbs are special because they change their ending and their stem as well. Some of these verbs are very common and useful in everyday situations. In this lesson, you will find a list of stem-changing verbs in Spanish, the rules to conjugate them in the present tense and how to use them in simple sentences and questions. Let’s start…
Spanish stem-changing verbs O to UE
Spanish stem-changing verbs need to change their stem spelling in order to keep a similar pronunciation of the verb in infinitive. They will be modified for all the pronouns, except for the subject pronouns VOS, VOSOTROS and NOSOTROS. The first rule says that when the vowel O is found in the stem, then there must be a stem change from O to UE. A common verb following this rule is DORMIR (to sleep), which can be divided into DORM (stem) and IR (ending). The letter O is found in DORM, so we must make a stem change from O to UE for all subject pronouns, except for VOS, VOSOTROS and NOSOTROS. Therefore, we must say “Yo duermo” not “Yo dormo” as it should be done if the verb were regular.
Some common Spanish stem-changing verbs O to UE are: dormir (to sleep), contar (to count), costar (to cost), encontrar (to find/to meet), recordar (to remember), volar (to fly), volver (to return) and almorzar (to eat lunch).
Sentences with stem-changing verbs O to UE
Yo duermo ocho horas todos los días
I sleep eight hours every day
Tú duermes demasiado durante el día
You sleep too much every day
Vos dormís como oso
You sleep like a bear
Él duerme solo algunas horas
He sleeps only a few hours
Dormimos en la misma habitación
We sleep in the same room
¿Vosotros dormís juntos?
Do you sleep together?
Ellos no duermen ahí
They do not sleep there
Spanish Stem changing verbs E to IE
The second rule we will learn says that if the vowel in the verb’s stem is E, then the vowel should change from E to IE. Similarly to the first rule, the stem change does not apply when the subject is VOS, VOSOTROS or NOSOTROS. The verb PENSAR is a very common stem-changing verb following this rule. The stem PENS- will change to PIENS- for the pronoun TÚ, for example, as in the sentence “Tú piensas”
Some common Spanish stem chaning verbs E to IE are: empezar (to begin), querer (to want), pensar (to think), divertirse (to have fun), despertarse (to wake up), sentir (to feel), mentir (to lie), cerrar (to close) and entender (to understand).
Sentences with stem-changing verbs E to IE
(Yo) Pienso que esa es una buena idea.
I think that is a good idea
¿(Tú) Piensas que esto es importante?
Do you think this is important?
Vos pensás que ella es bonita
You think she is beautiful
Ella piensa que está loco
She thinks that he is crazy
Pensamos que deberías quedarte.
We think you should stay
Vosotros pensáis que estoy enojado.
You think that I am angry
Ellos piensan que soy listo.
They think I am smart
Spanish stem changing verbs E to I
The third rule says that if the stem contains the vowel E, then we must change the stem from E to I only when the verb in infinitive ends in IR like SERVIR. For the verb SERVIR, we should say “Yo sirvo” not “Yo servo”.
Some common Spanish stem-changing verbs E to I are: servir (to serve), repetir (to repeat), seguir (to follow) and vestirse (to get dressed).
Sentences with stem-changing verbs E to I
Repito las canciones cuando me gustan
I repeat the songs when I like them
Tú repites demasiado
You repeat too much
Vos repetís eso una y otra vez.
You repeat that again and again
Ella repite los mismos errores.
She repeats the same mistakes
Nosotros repetimos las actividades
We repeat the activities
Vosotros repetís el viaje cada año.
You repeat the trip every year
Ellos repiten los pasos
They repeat the steps
Spanish stem changing verbs U to UE
The fourth rule is actually pretty simple and only affects one very common verb and that is JUGAR (to play), changing the stem from U to UE. JUGAR would be conjugated like this “Yo juego”, “Tú juegas”, “Él juega”, “Nosotros jugamos”, “Vosotros jugáis”, “Ellos juegan”.