Introduction
You already know the regular -AR / -ER / -IR patterns. Now it's time to tackle the verbs that break those rules. The good news: most irregularities follow predictable patterns.
Stem-Changing Verbs (Boot Verbs)
These verbs change their stem vowel in all forms except nosotros. The affected forms make a "boot" shape in a conjugation chart.
e → ie
Example: querer (to want)
| Person | Conjugation |
|---|---|
| yo | quiero |
| tú | quieres |
| él/ella | quiere |
| nosotros | queremos |
| ellos | quieren |
Other e → ie verbs: pensar, entender, preferir, tener (+ irregular yo), venir (+ irregular yo)
o → ue
Example: poder (to be able to)
| Person | Conjugation |
|---|---|
| yo | puedo |
| tú | puedes |
| él/ella | puede |
| nosotros | podemos |
| ellos | pueden |
Other o → ue verbs: dormir, volver, encontrar, contar, morir
e → i (only -IR verbs)
Example: pedir (to ask for)
| Person | Conjugation |
|---|---|
| yo | pido |
| tú | pides |
| él/ella | pide |
| nosotros | pedimos |
| ellos | piden |
Other e → i verbs: servir, repetir, seguir, vestirse
Yo-Irregular Verbs
These verbs are only irregular in the yo form. All other forms follow normal patterns.
| Verb | Yo Form | Pattern |
|---|---|---|
| hacer (to do) | hago | regular: haces, hace… |
| poner (to put) | pongo | regular: pones, pone… |
| salir (to leave) | salgo | regular: sales, sale… |
| traer (to bring) | traigo | regular: traes, trae… |
| conocer (to know) | conozco | regular: conoces, conoce… |
| saber (to know) | sé | regular: sabes, sabe… |
| dar (to give) | doy | regular: das, da… |
| ver (to see) | veo | regular: ves, ve… |
Fully Irregular Verbs
A few verbs follow no pattern at all and must be memorized.
Ir (to go)
voy, vas, va, vamos, van
Ser (to be)
soy, eres, es, somos, son
Haber (to have — auxiliary)
he, has, ha, hemos, han
Practice
Conjugate 'querer' for 'nosotros':
What is the yo form of 'hacer'?
'Ellos ___ (dormir) ocho horas.' Fill in the blank.
Which of these is NOT a stem-changing pattern?