Imperfecto de ser: era, eras, era | Spanish (Spain) Grammar

Spanish has roughly two hundred verbs that are irregular somewhere in their conjugation — but the imperfect of indicativo has only three irregular verbs in the entire language: ser, ir, and ver. The rest behave like clockwork. This page covers the first and most frequent of those three: the imperfect of ser. You'll see it everywhere in past narration because ser is the verb you reach for whenever you want to describe what something was — past identity, past time, past nature, past role.

The full paradigm

Subject	Form
yo	era
tú	eras
él / ella / usted	era
nosotros / nosotras	éramos
vosotros / vosotras	erais
ellos / ellas / ustedes	eran

Three things to lock in right away:

The only accent in the paradigm sits on éramos. Without it the word is misspelt.
The peninsular vosotros form is erais, without an accent. This surprises learners who have just memorized comíais, vivíais, teníais (which DO take an accent). The difference matters — see the next section.
Yo and él/ella/usted are identical (era). The pronoun or surrounding sentence resolves the ambiguity.

Cuando era pequeña, mi padre era profesor de matemáticas en un instituto de Vallecas.

When I was little, my father was a maths teacher at a secondary school in Vallecas.

Éramos cinco hermanos y la casa parecía siempre un campo de batalla.

We were five siblings and the house always felt like a battlefield.

Why erais takes no accent (and éramos does)

This is the single most missed accent question for ser in the imperfect. The Spanish stress rule says: a word ending in a vowel, n, or s is stressed on the second-to-last syllable by default. Any departure from that pattern requires a written accent.

E-ra-mos (default) — would be stressed on -ra-, but the actual stress falls on e-. The first syllable is the antepenultimate, so the word is proparoxytone (esdrújula), which always requires an accent: éramos.
E-rais (two syllables — the -ais is a single diphthong syllable) — the default stress lands on e-, which is where the stress actually goes. The word is paroxytone (llana), ending in s, default-stressed: no accent needed. erais.

This is exactly the same logic that gives you -abais without accent vs -íais with accent in regular -ar and -er/-ir verbs. In erais, the structure mirrors -abais: stress is on the syllable before -ais, default-stressed, no accent.

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The accent on éramos is mandatory not because the form is exotic but because Spanish stress rules require it. Any esdrújula (word stressed on the third-to-last syllable) takes an obligatory written accent. Éramos, éramos, éramos — every Spanish esdrújula you'll ever write follows the same rule.

A trap with er-style spelling

A small number of learners, having seen eras and eran, try to write the nosotros form as eramos (no accent) or éran (accent on the wrong word). Both are wrong.

Éramos — correct. Accent on the first e-.
Eramos — incorrect (missing the obligatory accent on an esdrújula).
Éran — incorrect (the third-person plural takes no accent because it's a llana ending in n, default-stressed; eran, not éran).
Eraís — incorrect (this is the most common A2 error: applying the -íais accent of comer/vivir to ser).

The rule of thumb for ser in the imperfect: only one accent, only on éramos.

What "ser" does in the imperfect

The imperfect of ser covers all the meanings that ser covers in any tense — identity, nature, role, time, origin, possession in formal speech — but shifted into the past as ongoing background, not as a bounded event. This is one of the highest-frequency verb forms in past narration.

Past identity and role

Mi tía era enfermera en el hospital de La Princesa antes de jubilarse.

My aunt was a nurse at La Princesa hospital before she retired.

El restaurante era nuestro favorito hasta que cerró durante la pandemia.

The restaurant was our favourite until it closed during the pandemic.

Telling time in the past

Telling the time in the past is always in the imperfect, never the preterite. Eran las tres cuando… — never fueron las tres cuando…

Eran las dos de la mañana cuando por fin se acabó la fiesta.

It was two in the morning when the party finally ended.

¿Qué hora era cuando llegasteis? — No sé, sería medianoche más o menos.

What time was it when you (guys) got there? — I don't know, midnight or so.

Past description (essential qualities)

La casa era enorme, con un patio interior y unos balcones de hierro forjado preciosos.

The house was huge, with an interior courtyard and beautiful wrought-iron balconies.

Eras muy reservado de adolescente — no te reconozco en quien eres ahora.

You were very reserved as a teenager — I don't recognize you in who you are now.

Telling past age (with the structure ser + age)

Wait — for age, Spanish uses tener, not ser. The structure is tenía veintidós años, not era veintidós años. We mention this because English speakers, having learned that ser covers identity, sometimes overextend it to age. Age in Spanish goes through tener, in any tense.

Source-language note for English speakers

English uses one verb (to be) for everything that Spanish splits between ser and estar. In the past, I was maps onto either era (essential, identifying) or estaba (state, location, condition). Choosing wrong sometimes yields a sentence that's grammatical but means the wrong thing.

Era profesor de matemáticas.

He was a maths teacher. (his profession, his identity)

Estaba enfermo aquel día.

He was ill that day. (a temporary state)

The English sentence "He was ill" feels equivalent to "He was a maths teacher" in surface structure, but Spanish refuses to treat them the same: identity goes through ser/era, condition goes through estar/estaba. See ser vs estar for the full breakdown.

The other English-speaker reflex to watch: in English, identity and description in the past can sound natural in either simple past (she was a teacher) or progressive (she was being a teacher, marginal). Spanish does not form the imperfect of ser with estar siendo in this sense — era profesora is the only natural form.

When ser goes preterite instead

This page is about the imperfect, but it's worth flagging: ser does have a preterite (fui, fuiste, fue, fuimos, fuisteis, fueron — identical to the preterite of ir), and the two tenses carry different meanings.

era (imperfect) — ongoing past identity or state. Era profesor = "he was a teacher" (during a stretch of time, with no closure implied).
fue (preterite) — a bounded chapter. Fue profesor diez años = "he was a teacher for ten years" (closed duration, then he stopped).

The minimal pair:

Mi tío era panadero.

My uncle was a baker. (his profession — ongoing background)

Mi tío fue panadero durante treinta años.

My uncle was a baker for thirty years. (closed chapter, with explicit duration)

If the sentence says how long something was true, the preterite often takes over. If it just describes what was the case at some past moment, the imperfect is the natural choice.

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The default for past description with ser is the imperfect (era, eran). The preterite (fue, fueron) sneaks in when a bounded duration appears (fue presidente cinco años, fueron novios dos meses). Without an explicit duration, almost always imperfect.

Some high-frequency uses worth memorizing

A few phrasings with ser in the imperfect appear so often in spoken Spain Spanish that you should treat them as set chunks:

érase una vez — "once upon a time" (the classic story opener). The -se is the residual reflexive of an old form of the verb. Modern variant: había una vez.
era de noche / era de día — "it was night / day". Imperfect for time-of-day descriptions.
¿qué hora era? — "what time was it?". Imperfect for past clock-readings.
éramos pocos y parió la abuela — fixed idiom, "as if things weren't bad enough" (literally "there were few of us and grandma gave birth").
era para — "it was meant for / it was so that…". Used in retrospective explanation: Era para que lo entendieras.

Érase una vez una niña que vivía en un pueblo muy pequeño cerca de Toledo.

Once upon a time there was a girl who lived in a very small village near Toledo.

Cuando salimos del bar ya era de noche y hacía un frío que pelaba.

When we left the bar it was already night and it was bitterly cold.

The vosotros example in detail

The peninsular vosotros form erais deserves a moment because it sounds different from what learners expect.

¿De dónde erais antes de mudaros aquí? — De Albacete, los dos.

Where were you (guys) from before you moved here? — From Albacete, both of us.

Vosotros erais los que organizabais las cenas de los viernes, ¿no?

You (guys) were the ones who used to organize the Friday dinners, right?

Note: erais is two syllables (e-rais), stressed on the first e-, no accent. In rapid speech it often sounds close to a single drawn-out eráis with the stress dragging onto the -ais — this is a phonetic drift, not a spelling change. Always write erais.

Common mistakes

❌ Cuando eramos pequeños, íbamos al parque cada tarde.

Wrong: éramos requires the accent on the first é.

✅ Cuando éramos pequeños, íbamos al parque cada tarde.

Correct: éramos with obligatory accent (esdrújula).

❌ ¿De dónde eraís?

Wrong: erais takes NO accent. Don't transfer the -íais pattern from comer/vivir.

✅ ¿De dónde erais?

Correct: erais without accent (paroxytone, default stress).

❌ Fueron las tres cuando por fin llegamos.

Wrong: telling time in the past is always imperfect, never preterite.

✅ Eran las tres cuando por fin llegamos.

Correct: eran las tres for the clock-reading, llegamos for the punctual event.

❌ Mi abuelo era panadero durante cuarenta años.

Wrong: bounded duration (cuarenta años) calls for the preterite.

✅ Mi abuelo fue panadero durante cuarenta años.

Correct: fue for the closed chapter with explicit duration.

❌ Era veinte años cuando me mudé a Madrid.

Wrong: age uses tener, not ser.

✅ Tenía veinte años cuando me mudé a Madrid.

Correct: tenía veinte años — Spanish uses tener for age in any tense.

Key takeaways

The imperfect of ser is era, eras, era, éramos, erais, eran.
Ser is one of only three irregular imperfects in all of Spanish (the others are ir and ver).
The only accent in the paradigm is on éramos. The vosotros form erais takes no accent — unlike -er/-ir forms like comíais, teníais, vivíais which do.
Yo and él/ella are identical (era); context disambiguates.
Use era for past identity, past clock-readings, past description, and the ongoing background sense of "was".
When you give an explicit duration (cinco años, dos meses), the preterite fue often replaces era. Without a duration, imperfect is the default.
Age in Spanish uses tener, not ser: tenía veinte años, never era veinte años.

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