Stem Changing Verbs "O">"Ue"

The main form of the verb is called the infinitive. The infinitive consists of two parts: the ending and the stem. The ending is the last two letters. There are only three different endings: -ar, -er, and -ir. The stem is everything else, except the ending.

hablar: ending = ar, stem = habl
comer: ending = er, stem = com
vivir: ending = ir, stem = viv

Some spanish verbs are called stem-changers because when they are conjugated, the stem changes in a predictable way. In one group of stem-changing verbs, the letter o in the stem changes to ue in all but the nosotros and vosotros forms. This particular type of stem-changing verb is found in all three verb types.

contar

yo cuento
tú cuentas
él, ella, Ud. cuenta

nosotros/as contamos
vosotros/as contáis

ellos, ellas, Uds. cuentan

For a more complete discussion of verbs that change o:ue click here.

Here are some common o:ue stem-changing verbs.

acordar
to agree, decide

acostar
to put to bed

almorzar
to eat lunch

aprobar
to approve

colgar
to hang

contar
to count, to tell

costar
to cost

demostrar
to demonstrate, prove

devolver
to return an object

dormir
to sleep

encontrar
to find

envolver
to wrap

forzar
to force

morder
to bite

morir
to die

mostrar
to show

mover
to move an object, to motivate

poder
to be able to

probar
to test, taste

recordar
to remember

resolver
to solve

rogar
to beg, pray

soler
to be in the habit of

sonar
to sound, ring

soñar
to dream

tostar
to toast

volar
to fly

volver
to return