Spanish 3: Irregular Verbs, Ser & Estar

Here is a fact that sounds like bad news and is not: the most common Spanish verbs are irregular. Ser, estar, ir, tener, hacer, poder, querer: you will meet them in almost every sentence. The good news is that most of them break the rules in a few repeating ways, and the ones that do not are a short list worth learning as blocks.

This piece sorts the irregular verbs into families, shows the core group in one table, gives you a trainer for them, and then deals with the pair every learner trips over: ser and estar, the two verbs for “to be”. Take it in two sittings if you like.

Stem-changers: the boot

In many verbs the vowel in the stem breaks into a diphthong, but only when it is stressed. Stress falls on the stem in yo, tú, él and ellos, and on the ending in nosotros and vosotros, so those two keep the plain vowel. Draw the shape on paper and it looks like a boot. The families are e → ie (quiero, queremos), o → ue (puedo, podemos), e → i (pido, pedimos) and, in one verb, u → ue (juego, jugamos).

Pattern	yo	nosotros	Also
e → ie	quiero	queremos	pensar, empezar, entender, preferir, cerrar
o → ue	puedo	podemos	volver, dormir, encontrar, contar, recordar
e → i	pido	pedimos	servir, repetir, seguir, elegir
u → ue	juego	jugamos	jugar only

Nothing in the spelling tells you whether a verb is a stem-changer: entender changes and aprender does not. Dictionaries mark it in brackets, querer (ie) or poder (ue), and the habit to build is to learn each new verb together with its change. The good news is that the pattern is one of the most frequent in the language, so what you learn here repays you every day.

A few verbs combine the boot with a spelling change: seguir gives sigo, sigues (the u disappears before o), elegir gives elijo (the g becomes j).

Yo-go verbs

A group of very common verbs adds -g- in the yo form only: tengo, vengo, hago, pongo, salgo, digo, traigo, caigo, valgo, and oigo (oír). Several also change their stem: tener gives tengo, tienes, but tenemos; decir gives digo, dices, but decimos. Not every irregular yo is a yo-go: doy, voy, soy, estoy, veo and sé are separate small cases.

Infinitive	Means	yo	Rest of the verb
tener	to have	tengo	tienes, tiene, tenemos, tienen
venir	to come	vengo	vienes, viene, venimos, vienen
hacer	to do, make	hago	regular: haces, hace, hacemos
poner	to put	pongo	regular: pones, pone, ponemos
salir	to go out	salgo	regular: sales, sale, salimos
decir	to say	digo	dices, dice, decimos, dicen

Spelling changes that protect a sound

These verbs are not really irregular: the spelling changes so that the sound stays the same. Vowel + -cer/-cir adds a z in yo: conozco, traduzco. In -ger/-gir verbs g becomes j before o: escojo, dirijo. Seguir gives sigo; vencer gives venzo. -uir verbs add y (construyo), and enviar and continuar put the stress on the weak vowel (envío, continúo) in the boot shape. You need not memorise a list: when a form looks odd, ask what sound the spelling is protecting.

The core irregulars

These are worth learning as blocks, because you will meet them in almost every sentence:

	yo	tú	él	nosotros	vosotros	ellos
ser	soy	eres	es	somos	sois	son
estar	estoy	estás	está	estamos	estáis	están
ir	voy	vas	va	vamos	vais	van
haber	he	has	ha	hemos	habéis	han
tener	tengo	tienes	tiene	tenemos	tenéis	tienen
hacer	hago	haces	hace	hacemos	hacéis	hacen
poder	puedo	puedes	puede	podemos	podéis	pueden
querer	quiero	quieres	quiere	queremos	queréis	quieren
decir	digo	dices	dice	decimos	decís	dicen
saber	sé	sabes	sabe	sabemos	sabéis	saben
dar	doy	das	da	damos	dais	dan
ver	veo	ves	ve	vemos	veis	ven
venir	vengo	vienes	viene	venimos	venís	vienen
oír	oigo	oyes	oye	oímos	oís	oyen

The impersonal hay (from haber) means “there is” and “there are”: Hay un libro. Hay dos libros. It never changes for number. Note that haber is not “to have” in the sense of owning: that is tener.

Train the irregular forms

The same trainer as before, now with the irregular groups. Switch groups on and off with the first row of buttons: stem-changers, yo-go and spelling changes, key irregulars, and the accent and y changes. Start with one group, drill it until it feels easy, then add the next. The notes after each answer explain the pattern behind the form.

Look up any verb, and who says what

Verb lookup

Choose a verb and a region. Letters that differ from the regular pattern are highlighted; forms nobody uses in that region are dimmed.

Verb

Without JavaScript, see the tables above. In Spain the six forms are all used; in most of Latin America vosotros is replaced by ustedes; in Argentina and Uruguay vos replaces tú.

Ser or estar: identity versus state

Spanish has two verbs for “to be”. A workable first rule: ser says what something is, estar says how or where it is right now. Use ser for identity and definition (Madrid es la capital), professions (Soy profesora), origin (Somos de Colombia), lasting traits (Mi hermano es alto), and for days, dates and clock times (Hoy es lunes. Son las cinco). Use estar for states that can change (Estoy cansada), for the location of things and people (El libro está en la mesa), and for actions in progress (Estoy leyendo, to come in a later piece).

Two things to know early. First, the location of an event takes ser: La fiesta es en mi casa. Second, many adjectives change meaning with the verb, which is where the choice carries real information:

Adjective	With ser	With estar
listo	clever	ready
aburrido	boring	bored
malo	bad (a bad person or thing)	ill, or gone off (food)
rico	rich	tasty
verde	green	unripe
seguro	safe	sure, certain

A way to remember the split is to ask: is this a description of what the thing is, or the condition it happens to be in now? A teacher es tall; a teacher está tired. The rule of thumb covers most everyday sentences, and you will pick up the rest through input.

Common mistakes

• Ser for a feeling. Soy cansado means roughly “I am tiresome”; use estoy cansado for being tired.
• Estar for a profession. Estoy profesor is wrong; use soy profesor.
• Ser for age and hunger. Spanish says “have”: tengo veinte años, tengo hambre, tengo sed, tengo frío, tengo calor, tengo sueño, tengo miedo, tengo prisa. Never soy hambre or estoy veinte años.
• Regularising an irregular. The yo form of tener is tengo, not tieno, and of hacer it is hago, not hazo. When a yo form looks too simple, check it.
• Breaking the boot. Nosotros quieremos is wrong; the stress is on the ending, so the stem keeps its plain vowel: queremos.
• Hay versus está. Use hay to say that something exists (Hay un banco aquí); use estar to say where a known thing is (El banco está allí).

Your next four days

Day	Trainer	Outside the page
1	Stem-changers only; yo, tú, él	Say five sentences with quiero, puedo, prefiero.
2	Add nosotros, so you feel the boot end	Say what you and a friend want to do today.
3	Yo-go and the key irregulars	Write five true sentences with tener, ser, estar, hacer, ir.
4	Everything; then the ser or estar sorter	Describe your room and your mood in four sentences.

What sticks

• Stem changes happen only where the stress is on the stem: quiero, but queremos.
• Learn a stem-changer together with its change: querer (ie), poder (ue), pedir (i).
• Yo-go verbs add a g in the first person only: tengo, hago, pongo, salgo.
• Spelling changes protect a sound: conozco, escojo, sigo.
• Learn ser, estar, ir, haber, tener and the other core verbs as blocks.
• Ser is for what something is; estar is for how or where it is right now. Events take ser, and some adjectives change meaning.
• Age, hunger, thirst, cold and fear use tener, not ser or estar.