With stem-changing verbs, the stem vowel undergoes a change in the present tense. Follow the links to the right for an explanation of the most common stem-changing verb types.

Let's look at some example sentences:

volar, poder - (o) changes to (ue)
Yo vuelo a México.
I fly to Mexico.
¿Puedo tomarlos juntos?
Can I take them together?

querer - (e) changes to (ie)
Quiero ser médico.
I would like to be a doctor.
¿A quién quieres enviar el dinero?
Who do you want to send money to?

pedir - (e) changes to (i)
Le pido que compre un regalo.
I ask you to buy a gift.
¿Por qué no le pides la bicicleta?
Why don't you ask him for the bicycle?

jugar - (u) changes to (ue)
Yo juego con el perro.
I play with the dog.