The regular -ir endings

Strip the -ir from the infinitive and bolt on the endings below. They are identical to the -er endings except in the nosotros and vosotros forms, where -ir keeps its i (-imos, -ís) instead of the -er e (-emos, -éis).

Vivo en Madrid desde hace diez años. ("I have lived in Madrid for ten years.")

That is the whole regular pattern. If every -ir verb behaved like vivir we would be done. Most do not.

Stem-changing -ir verbs

-ir brings a vowel-shift pattern that -ar and -er do not have: e>i. The stressed e in the stem becomes i in every form except nosotros and vosotros (because stress falls on the ending there, not the stem).

The headline e>i verbs are pedir (to ask for), seguir (to follow), conseguir (to obtain), repetir (to repeat) and servir (to serve). Seguir adds a spelling wrinkle - the silent u after g is there to keep the g hard before e and i, but in the yo form the ending is -o, so the u is dropped:

The older e>ie pattern from -ar/-er verbs also shows up in -ir: sentir (to feel) gives siento, sientes, siente, sentimos, sentís, sienten. Preferir works the same way. And the o>ue pattern is present too: dormir (to sleep) gives duermo, duermes, duerme, dormimos, dormís, duermen. Morir (to die) is identical: muero, mueres, muere, morimos, morís, mueren.

The big irregulars

Five -ir verbs do most of the damage. They are also five of the verbs you will use every day, so memorise them as a block.

ir (to go) is totally suppletive - the present forms share no letters with the infinitive:

voy, vas, va, vamos, vais, van.

decir (to say) has an irregular yo form plus the e>i stem change:

digo, dices, dice, decimos, decís, dicen.

venir (to come) has an irregular yo form plus the e>ie stem change:

vengo, vienes, viene, venimos, venís, vienen.

salir (to leave, to go out) is regular everywhere except the yo form:

salgo, sales, sale, salimos, salís, salen.

oír (to hear) is the messiest of the lot: irregular yo, a spelling y in the tú, él and ellos forms, and an accent on the í in the nosotros and vosotros forms to mark the stress:

oigo, oyes, oye, oímos, oís, oyen.

These five verbs alone are most of what makes -ir feel hard. Drill them until they come out without thinking and the rest of the class is much less intimidating.

The easy ones

A useful chunk of common -ir verbs are completely regular. Conjugate them by reflex using the vivir endings: vivir itself, abrir (to open), ocurrir (to happen). Conseguir is "regular" in the sense that its only oddity is the silent-u spelling rule plus the inherited e>i from seguir - no new pattern to learn.

The 13 -ir verbs in this curriculum

Sorted by conjugation behaviour, from most irregular to most regular:

How to internalise -ir conjugation

Drill the regular endings first - they are nearly identical to -er, with only the nosotros (-imos) and vosotros (-ís) differing. Once those are automatic, learn ir, decir, venir, salir and oír in full as a single block. You will use all five every day, often in the same sentence, so the investment pays back fast. After that, the e>i stem change is the one genuinely new mechanic that -ir brings (-ar and -er do not have it), so put pedir, seguir and servir on the same flashcards as the regular endings. The o>ue and e>ie patterns will already be familiar from -ar and -er verbs; here they just apply to a handful of high-frequency -ir verbs (dormir, morir, sentir, preferir).

Pick six verbs from the table above and conjugate each one out loud through all six persons. Do that three days running and the system will start to feel small rather than large.