Las tres conjugaciones: -ar, -er, -ir

Every Spanish verb belongs to one of three classes — three conjugaciones — identified by the last two letters of the infinitive: -ar, -er, or -ir. That tiny ending isn't a label; it determines which set of personal endings the verb takes in every tense and mood. Get a verb's class right and the rest of the conjugation falls into place. Get it wrong and you produce something that sounds either childish or just impossible to Spanish ears.

This page lays the three classes side by side, shows where they overlap, and pinpoints the places where they genuinely diverge.

Relative frequency: -ar dominates

The three classes are not equal in size. By the most generous count, about 90% of Spanish verb infinitives end in -ar. The remaining ~10% is split between -er and -ir, with -er slightly larger.

More importantly, -ar is the only productive class. Every new verb that enters Spanish — through borrowing, technology, or slang — gets the -ar ending. Tuitear, googlear, wasapear, clickar, escanear, resetear, zoomear are all twentieth- or twenty-first-century coinages, and all of them are -ar verbs. The -er and -ir classes are essentially closed: no one is going to invent a new verb ending in -er or -ir in 2026.

What this means for a learner:

• Whenever you guess at a verb you don't know, guess -ar unless you have a reason not to.
• The -er and -ir verbs you encounter are a finite list — common but countable.

The three present-indicative paradigms, side by side

Here are the present-indicative endings for all three classes — peninsular Spanish, with vosotros in bold:

Take a moment to look at this table — really look at it. Two patterns jump out.

Pattern 1: yo is always -o

Every single regular verb in every single class takes -o in the yo form of the present indicative. That's a free win. Whatever new verb you meet, if it's regular, yo of the present is the stem plus -o.

Pattern 2: -er and -ir are almost identical

Compare comer and vivir. They differ in only two places:

• nosotros: comemos vs vivimos
• vosotros: coméis vs vivís

Everywhere else, -er and -ir take exactly the same ending. Yo, tú, él, and ellos forms are identical: como / comes / come / comen vs vivo / vives / vive / viven.

This is hugely useful: if you can conjugate -er verbs, you can almost conjugate -ir verbs. You just need to remember the two places where they split.

Three model verbs

We'll use these three throughout the guide:

• hablar (to speak) — model -ar verb
• comer (to eat) — model -er verb
• vivir (to live) — model -ir verb

Hablar in action

Comer in action

Vivir in action

For complete conjugation tables and usage notes, see the per-class pages:

• Regular -ar verbs
• Regular -er verbs
• Regular -ir verbs

What's the same across all three classes

It's worth pausing on the overlap, because it shrinks how much you actually have to memorize.

In the present indicative:

• yo is always -o
• él / ella / usted ending is -a (for -ar) or -e (for -er and -ir)
• ellos / ellas / ustedes ending is -an or -en
• The vowel that marks the class (the "thematic vowel" — a for -ar, e for -er, i for -ir) shows up in the endings: -amos, -as, -an vs -emos, -es, -en.

Once you know the thematic vowel of a verb, you can predict most of its endings.

Other tenses follow the same skeleton

The three-class system doesn't just shape the present. Every tense in Spanish has three sets of endings — one per class — and they all share the same basic skeleton.

A small preview from other tenses:

Imperfect:

Preterite:

Look at the preterite: -er and -ir fully collapse — they share identical endings in every person. That collapse is general: in most tenses other than the present, -er and -ir verbs use the same endings.

A useful rule of thumb: outside the present, -er and -ir are essentially one class.

You can't tell the class from the meaning

For an English speaker, an awkward truth: there is no semantic clue to a verb's class. Verbs of motion are split across all three (caminar -ar, correr -er, salir -ir). Verbs of speech are too (hablar -ar, responder -er, decir -ir). Verbs about food: comer -er, beber -er, cenar -ar.

You can't infer the class from a related noun, either. The noun trabajo (work) goes with trabajar (-ar); the noun vida (life) goes with vivir (-ir); the noun comida (food) goes with comer (-er). The noun shape predicts nothing.

The practical consequence: every time you learn a new verb, learn it with its ending intact — not as habl- but as hablar. The infinitive is the only piece of information that fully identifies the class.

Some common -er verbs (peninsular sample)

A working list to start from. These are all regular except where noted:

Some common -ir verbs (peninsular sample)

You'll notice the -ir list is shorter overall. That's just the reality of the class size — -ir verbs are the smallest group, but several of them (vivir, escribir, abrir) are extremely high-frequency.

A note on register and dialect

In Spain, the vosotros row is essential — you'll hear coméis, vivís, habláis every day. In Latin America, ustedes covers both familiar and formal plural, so those vosotros endings only appear in books, songs, or speeches. If your previous Spanish learning skipped vosotros, this is the moment to add it: every regular -ar takes -áis, every regular -er takes -éis, every regular -ir takes -ís. Three endings, infinite payoff.

Common mistakes

The last error is the classic -er/-ir mix-up. Remember the rule: in the present they diverge in nosotros and vosotros. Outside the present they collapse — in the preterite, future, conditional, and imperfect, you can treat them as one class.

Key takeaways

• Three classes by ending: -ar (~90%), -er, -ir.
• -ar is the only productive class. All new Spanish verbs are -ar.
• In the present indicative, -er and -ir verbs diverge only in nosotros (-emos/-imos) and vosotros (-éis/-ís).
• Every regular yo form ends in -o, across all three classes.
• The class lives in the infinitive — always learn verbs with their ending intact.
• Vosotros endings: -áis / -éis / -ís. Drill them.

The next page tackles a related question: what does it mean for a Spanish verb to be irregular? See Verbos regulares e irregulares.