1. Conjugate stem changers in the present tense

2. Stem changing infinitives
Stem changing infinitives are named for what they do– change in the stem. You are going to make some alteration of the stem before adding the verb endings. You will use the endings you already know. The hardest part of stem changers is knowing which ones change and which ones don’t.

3. Stem changers
There are 4 different ways a stem changing infinitive can change (4 categories). The first is uue. It is the smallest category with only one infinitive jugar = to play (sports)

4. Jugar = to play (sports)
Separate the stem and the infintive ending. Jug- is the stem Make the stem change uue The new stem is jueg- Put it in the conjugation box EXCEPT nosotros and vosotros. Nosotros and Vosotros do not make the stem change.

5. Jugar = to play sports Yo Jueg- Nosotros/as Jug- Tú Vosotros/as Él
Ella jueg-
Ud.
Ellos
Ellas jueg-
Uds.
Now just add the regular –ar endings.

6. Jugar = to play sports Yo Juego Nosotros/as Jugamos Tú Juegas
Vosotros/as
Jugáis Él
Ella juega
Ud.
Ellos
Ellas juegan
Uds.

7. Stem changers
The second category is one of the largest.
It is oue.
Encontrar = to find is a stem changer.
It is the same steps as jugar.
Other examples include: acostar (to lie down), almorzar (to eat lunch), contar (to count), costar (to cost), devolver (to return something), dormir (to sleep), poder (can/to be able to), volver (to return)

8. Encontrar = to find
First separate the stem from the infinitive ending. Encontr- is the stem. Make the stem change oue New stem encuentr- Put into box– remember it will look like a boot… they are called boot verbs as well.

9. Encontrar = to find encuentro encontramos encuentras encontráis
encuentran

10. Stem changers The third category is again large. It is eie.
preferir = to prefer is a stem changer.
It is the same steps as jugar.
*When there is more than one vowel that could possibly make the change, choose the vowel closest to the verb ending.

11. Other e ie verbs
Cerrar (to close), Comenzar (to begin), Despertar (to wake up),
Divertir (to entertain/ amuse),
Empezar (to begin), Entender (to understand), Pensar (to think), Perder (to lose),
Querer (to want),
Recomendar (to recommend)

12. Preferir = to prefer
First separate the stem from the infinitive ending.
prefer- is the stem.
Make the stem change eie
New stem prefier-
Put into box– remember it will look like a boot… they are called boot verbs as well.

13. preferir = to prefer prefiero preferimos prefieres preferís prefiere
prefieren

14. Stem changers The last category is a smaller one. It is ei.
servir = to serve is a stem changer.
It is the same steps as jugar.

15. servir = to serve First separate the stem from the infinitive ending.
serv- is the stem.
Make the stem change ei
New stem sirv-
Put into box– remember it will look like a boot… they are called boot verbs as well.

16. servir = to serve
sirvo
servimos
sirves
servís
sirve
sirven

17. ei
There are some rules that can help you distinguish between e i and e ie. In order to be e i, the infinitive must end in –ir. Now, that could be other categories as well, but –ar and –er cannot be e i . MR C VeSPeRS is also a way to help if you are needing a pneumonic device.

18. MR. C VeSPeRS M- medir (to measure) R – reír (to laugh)
C – conseguir (To get/ to obtain)
V – vestir(se) (to dress)
S- servir (to serve)
P – pedir (to ask for)
R- repetir (to repeat)
S- seguir (to follow/ to continue)

19. E → I Verbs
MR. C VeSPeRS does not include all the stem changers in this category. Another infinitive is Sonreír (to smile)

20. Stem Changers
I cannot give you a rule as to which verbs stem change and which ones don’t. These are just something that you have to learn as you continue to use Spanish.
Don’t forget-you have already learned all of the u → ue stem-changers.