1. The Present Tense of Stem-Changing Verbs: e  ie, o  ue
(El tiempo presente de los verbos de cambio radical)

2. There are three types or classes of “boot” verbs.
There is a fairly large group of verbs in Spanish that undergo changes in their stem when conjugated in the present tense. These changes occur only in the first and second persons singular and third persons singular and plural.
When a line is drawn around the forms that change, the resulting shape vaguely resembles a boot or high-top shoe; thus, these verbs are sometimes informally called “boot” verbs.
There are three types or classes of “boot” verbs.

3. We’ll use entender, to understand, as an example of this type.
Type 1: e  ie
We’ll use entender, to understand, as an example of this type.
entiendo
entiendes
entiende
entendemos
entendéis
entienden

4. Here are some other common e  ie verbs:
empezar, comenzar
to begin
entender
to understand
querer
to want, to love
preferir
to prefer

5. E-IE
nevar- to snow
merendar- to snack
cerrar- to close
pensar- to think
perder- to lose

6. We’ll use poder, to be able, as an example of this type.
Type 2: o  ue
We’ll use poder, to be able, as an example of this type.

7. *Costar is normally used only in the third persons.
Here are some other common o  ue verbs:
costar*
to cost
dormir
to sleep
encontrar
to find
almorzar
to have lunch
volver
to return, to come back
*Costar is normally used only in the third persons.

8. O-UE llover- to rain recordar- to remember devolver- to return (items) encontrar- to find

9. The verbs querer and preferir
Expressing desires and preferences
Querer and preferir are important stem-changing verbs that have multiple uses.

10. When used with a thing as the direct object, querer means to want.
quiero
quieres
quiere
queremos
queréis
quieren
When used with a thing as the direct object, querer means to want.

11. ¿Quiere un sándwich de pollo?
Sí, y quiero papas fritas también, por favor.

12. When used with a person as the direct object, querer means to love.
quiero
quieres
quiere
queremos
queréis
quieren
When used with a person as the direct object, querer means to love.

13. Quiero mucho a su hija, señor Vega.

14. Preferir, of course, means to prefer.
prefiero
prefieres
prefiere
preferimos
preferís
prefieren
Preferir, of course, means to prefer.

15. ¿Quiere un sándwich de pollo?
No señor, prefiero una hamburguesa.

16. FIN