Imperfect of Ser | Portuguese (Portugal) Grammar

The verb ser (to be) is one of only four verbs that are irregular in the imperfect tense. Its stem changes completely -- from the sou/és/é of the present and the fui/foi of the preterite to er- in the imperfect. Despite its irregularity, ser in the imperfect is one of the most frequently used verb forms in Portuguese. Describing how things were, what people were like, what time it was -- all of this depends on the imperfect of ser.

Conjugation

Person	Form	English
eu	era	I was / I used to be
tu	eras	you were / you used to be
ele / ela / você	era	he/she was; you were
nós	éramos	we were / we used to be
(vós)	(éreis)	(you all were)
eles / elas / vocês	eram	they were; you all were

The vós form éreis is archaic and appears only in older texts. Modern European Portuguese uses vocês with the third person plural form eram.

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The written accent on éramos is mandatory -- it marks the stressed syllable. Without it, the stress would shift and the word would be wrong. This is the only form in the conjugation that carries an accent. Note also that eu and ele/você share the same form era, just as they do in every imperfect conjugation.

The stem er- bears no resemblance to the present tense (sou, és, é, somos, são) or the preterite (fui, foste, foi, fomos, foram). It is a completely unique stem used only in the imperfect. Fortunately, the endings (-a, -as, -a, -amos, -am) follow the same pattern as regular imperfect verbs, so once you know the stem, the rest is predictable.

Past identity and characteristics

The imperfect of ser describes what someone or something was as an ongoing quality -- profession, personality, nationality, appearance, or any defining trait.

Ele era professor de matemática.

He was a maths teacher.

Ela era muito bonita e simpática.

She was very beautiful and kind.

Os meus avós eram portugueses.

My grandparents were Portuguese.

These are not events that happened at a specific moment. They are descriptions of how things were over time -- exactly the kind of meaning the imperfect carries.

Past descriptions and scene-setting

When you describe what a place, an object, or a situation was like, era/eram provides the background.

A cidade era mais pequena naquela época.

The city was smaller back then.

O céu era azul e o mar estava calmo.

The sky was blue and the sea was calm.

Notice in the second example how era (ser, imperfect) and estava (estar, imperfect) work side by side. The sky's colour is a characteristic (ser); the sea's calm is a temporary state (estar). Both are imperfect because both describe the ongoing scene.

Past time and age

Telling time in the past and stating ages both use the imperfect of ser.

Portuguese	English	Note
Era uma hora.	It was one o'clock.	singular -- era
Eram três da tarde.	It was 3 PM.	plural -- eram
Eram oito da manhã quando saí.	It was 8 AM when I left.	imperfect sets the scene

Eu era criança quando nos mudámos para o Porto.

I was a child when we moved to Porto.

"Used to be"

When ser in the imperfect describes how life or the world used to be, it often pairs with time markers like antigamente, naquela altura, or dantes.

A vida era mais simples antigamente.

Life used to be simpler in the old days.

Dantes, a aldeia era muito sossegada.

In the past, the village used to be very quiet.

Era vs foi -- imperfect vs preterite of ser

This is one of the most important contrasts in Portuguese past tenses. Both era and foi translate as "was" in English, but they describe different kinds of past.

Era (imperfect) = was, as an ongoing state, background, or description. No clear boundaries.
Foi (preterite) = was, as a completed event, a finished judgement, or a bounded period.

Era (imperfect)	Foi (preterite)
O filme era bom. (describing its nature)	O filme foi bom. (overall judgement after watching)
A reunião era às três. (the schedule, a standing plan)	A reunião foi às três. (it took place, it's done)
Ele era simpático. (that was his personality)	Ele foi simpático. (he was nice on that occasion)
A casa era velha. (describing the house)	A viagem foi longa. (the trip is over, total judgement)

O jantar era sempre às oito.

Dinner was always at eight. (habitual -- imperfect)

O jantar foi às oito.

Dinner was at eight. (one-time event -- preterite)

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A practical test: if you can add "always" or "used to" and the sentence still makes sense, use the imperfect (era). If the sentence describes a single completed event or a final verdict, use the preterite (foi). See Preterite of Ser and Ir for the full preterite conjugation.

Era uma vez...

The phrase era uma vez -- "once upon a time" -- is the classic opening of fairy tales and stories in Portuguese. It uses the imperfect because the story sets an ongoing scene in an indefinite past.

Era uma vez uma princesa que vivia num castelo muito alto.

Once upon a time there was a princess who lived in a very tall castle.

Notice that vivia (imperfect of viver) continues the scene-setting. The imperfect dominates the opening of any narrative because it paints the background before the action begins.

Quando era criança / jovem

The phrases quando era criança (when I was a child) and quando era jovem (when I was young) are among the most common imperfect constructions in Portuguese. They always use era, never foi, because they describe an extended period, not a single event.

Quando era jovem, vivia no campo e andava sempre descalço.

When I was young, I lived in the countryside and always went barefoot.

Quando éramos crianças, íamos à praia todos os verões.

When we were children, we went to the beach every summer.

These sentences typically introduce a series of habitual actions in the imperfect -- vivia, andava, íamos -- all painting a picture of what life used to be like.

Common mistakes

1. Using foi where era is needed. Descriptions and ongoing states require the imperfect. Saying A casa foi grande when you mean "The house was big (as a description)" is incorrect -- it should be A casa era grande. Reserve foi for completed events and judgements.

2. Confusing era (verb) with era (noun). The word era also exists as a noun meaning "era" or "age" (a era digital -- the digital age). Context always makes the distinction clear, but be aware that they are different words.

3. Forgetting the accent on éramos. Writing eramos without the accent is a spelling error. The accent on the é is required in the first person plural.

4. Using ser where estar belongs. Even in the imperfect, the ser/estar distinction applies. Eu era cansado suggests tiredness is a permanent trait. If you mean you were tired at that moment, use estava cansado. For permanent characteristics, use era; for temporary states, use estava. See Ser, Estar, and Ficar for the full distinction.

For the overall imperfect tense system, see Imperfect Overview. For the other key irregular verb in this tense, see Imperfect of Ter. To compare the imperfect with the preterite in depth, see Preterite vs Imperfect.