Stem-changing verbs in Spanish change the vowel sound in the stem when conjugated, except in the "nosotros" form. There are three types of stem changes: e to ie, o to ue, and e to i. Examples are provided for each type of stem change, including irregular "yo" forms for some verbs like "tener", "venir", "seguir", and "conseguir".

2. Stem-changing verbs are different from regular
verbs because when you conjugate these verbs,
not only do you change the endings but you also
change the stem (except for the nosotros form).
Quick Review:
A verb has two parts - the stem and the ending.
For example: perder (to lose)
Perd + er
Stem Ending

3. In verbs that have an e to ie change, when you
conjugate the verb, you change the ‘e’ in the stem to
‘ie’ in all forms except the nosotros form.

5. cerrar – to close
comenzar – to begin
empezar – to begin
pensar – to think
Examples of e  ie Stem-Changing verbs in the
present tense:
entender – to understand
perder – to lose
querer – to want
preferir – to prefer
referir – to refer
sentir – to feel, to regret

6. Tener (to have) and Venir (to come) are also e-ie stem-changing
verbs but these verbs have an irregular ‘yo’ form.
TENER – to have
Yo tengo Nosotros tenemos
Tú tienes
Él
Ella tiene
Usted
Ellos
Ellas tienen
Ustedes
VENIR – to come
Yo vengo Nosotros venimos
Tú vienes
Él
Ella viene
Usted
Ellos
Ellas vienen
Ustedes

7. In verbs that have an o to ue change, when you
conjugate the verb, you change the ‘o’ in the stem to
‘ue’ in all forms except the nosotros form.

9. almorzar – to eat lunch
contar– to count
colgar – to hang
costar – to cost
encontrar – to meet to find
mostrar – to show
recordar – to remember
volar – to fly
Examples of o  ue Stem-Changing verbs in the
present tense:
poder – to be able to
volver – to return
llover – to rain
dormir – to sleep

10. In the verb, Jugar (to play) the stem-change is u - ue.
Jugar – to play
Yo juego Nosotros jugamos
Tú juegas
Él
Ella juega
Usted
Ellos
Ellas juegan
Ustedes

11. In verbs that have an e to i change, when you
conjugate the verb, you change the ‘e’ in the stem to
‘i’ in all forms except the nosotros form.

13. pedir – to ask for, to order
repetir – to repeat
servir – to serve
seguir – to follow, to continue
conseguir – to get
Examples of e  i Stem-Changing verbs in the
present tense:

14. The verbs Seguir (to follow, to continue) and Conseguir (to get) are
e-i stem-changing verbs but these verbs have an irregular ‘yo’ form.
You drop the letter ‘u’ in the Yo form.
SEGUIR – to follow, to continue
Yo sigo Nosotros seguimos
Tú sigues
Él
Ella sigue
Usted
Ellos
Ellas siguen
Ustedes
CONSEGUIR – to get
Yo consigo Nosotros conseguimos
Tú consigues
Él
Ella consigue
Usted
Ellos
Ellas consiguen
Ustedes