Ser is one of Portuguese's two verbs for to be — the one for identity, essence, origin, permanent qualities, and the time/place of events. Its partner estar covers temporary states and current location. Ser is among the most irregular verbs in the language: its forms come from several different Latin verbs fused together, which is why the present, preterite, and imperfect look almost unrelated to each other. The most startling fact for learners: ser's preterite (fui, foi, fomos, foram) is identical to that of ir (to go) — context alone tells them apart.
Presente do indicativo
There is no shortcut here — these forms must be memorized whole. They are some of the first words a learner meets.
| Pronoun | Form |
|---|---|
| eu | sou |
| tu | és |
| você / ele / ela | é |
| nós | somos |
| vocês / eles / elas | são |
Note the accents: é (acute) and são (tilde). In Brazil você é is the everyday form; tu és is mostly literary or regional (the South and parts of the North use tu, though often with the você verb form in casual speech).
Eu sou brasileiro, mas moro fora há dez anos.
I'm Brazilian, but I've lived abroad for ten years.
Quem são essas pessoas na foto?
Who are these people in the photo?
A festa é na casa da Marina, não no clube.
The party is at Marina's place, not at the club.
Pretérito perfeito
Here is the famous overlap: ser and ir share the exact same preterite. Fui ao mercado (I went to the market) and Fui professor (I was a teacher) use identical forms.
| Pronoun | Form |
|---|---|
| eu | fui |
| tu | foste |
| você / ele / ela | foi |
| nós | fomos |
| vocês / eles / elas | foram |
Telling them apart is easy in practice: ser is followed by a noun/adjective (foi médico, foi difícil), while ir is followed by a destination or a/para (foi ao Rio, foi embora).
A viagem foi maravilhosa, valeu cada centavo.
The trip was wonderful, worth every penny.
Eles foram os melhores chefes que já tive.
They were the best bosses I've ever had.
Pretérito imperfeito
The imperfect comes from yet another Latin source. It is the tense for "used to be" and for description in the past.
| Pronoun | Form |
|---|---|
| eu | era |
| tu | eras |
| você / ele / ela | era |
| nós | éramos |
| vocês / eles / elas | eram |
Note the accent on éramos. Eu and ele/ela are identical (era) — context supplies the subject.
Quando eu era criança, a gente morava no interior.
When I was a kid, we lived in the countryside.
Era uma vez uma princesa que vivia num castelo.
Once upon a time there was a princess who lived in a castle.
Futuro do presente & futuro do pretérito (conditional)
Both are built regularly on the infinitive ser-, so these are the "easy" tenses.
| Pronoun | Futuro do presente | Futuro do pretérito |
|---|---|---|
| eu | serei | seria |
| tu | serás | serias |
| você / ele / ela | será | seria |
| nós | seremos | seríamos |
| vocês / eles / elas | serão | seriam |
In speech the simple future is often replaced by ir + ser: vai ser rather than será. (informal)
O show vai ser no sábado, então se programe.
The show is going to be on Saturday, so plan accordingly.
Seria ótimo se você pudesse vir também.
It would be great if you could come too.
Presente do subjuntivo
Built on an irregular sej- stem.
| Pronoun | Form |
|---|---|
| eu | seja |
| tu | sejas |
| você / ele / ela | seja |
| nós | sejamos |
| vocês / eles / elas | sejam |
Espero que a reunião seja rápida, tenho mil coisas pra fazer.
I hope the meeting is quick, I have a thousand things to do.
Tomara que sejam só boas notícias.
Hopefully it's all good news.
Imperfeito & futuro do subjuntivo
The imperfect subjunctive uses the foss- stem (related to the preterite foi), and the future subjunctive uses for- — which is also shared with ir.
| Pronoun | Imperfeito do subjuntivo | Futuro do subjuntivo |
|---|---|---|
| eu | fosse | for |
| tu | fosses | fores |
| você / ele / ela | fosse | for |
| nós | fôssemos | formos |
| vocês / eles / elas | fossem | forem |
Note the circumflex on fôssemos. As with the preterite, for / fosse are shared with ir; only context distinguishes "if I were" (ser) from "if I went" (ir).
Se eu fosse você, não aceitaria essa proposta.
If I were you, I wouldn't accept that offer.
Seja o que for, a gente resolve juntos.
Whatever it may be, we'll sort it out together.
Imperativo
The você imperative comes from the subjunctive (seja). The tu affirmative is sê (literary; rare in everyday Brazilian speech).
| Pronoun | Afirmativo | Negativo |
|---|---|---|
| tu | sê (literary) | não sejas |
| você | seja | não seja |
| nós | sejamos | não sejamos |
| vocês | sejam | não sejam |
Seja sincero comigo: você gostou ou não?
Be honest with me: did you like it or not?
Non-finite forms
| Form | Result |
|---|---|
| Infinitivo | ser |
| Infinitivo pessoal (eu / você / ele) | ser |
| Infinitivo pessoal (nós) | sermos |
| Infinitivo pessoal (vocês / eles) | serem |
| Gerúndio | sendo |
| Particípio | sido |
Sendo bem honesto, eu preferia ficar em casa.
Being totally honest, I'd rather stay home.
When to use ser (vs. estar)
English has only one "to be," so the ser/estar split is the single hardest thing about this verb for English speakers. Use ser for:
- Identity / definition: Ela é médica. (She's a doctor.)
- Nationality, origin: Sou de São Paulo. (I'm from São Paulo.)
- Inherent / permanent qualities: O Brasil é enorme. (Brazil is huge.)
- Material / possession / relationship: A mesa é de madeira. / Este livro é meu. / Ele é meu primo.
- Time and dates: Hoje é segunda. / São três horas.
- The location of an event (not of an object): A reunião é na sala 3. (The meeting is in room 3.)
The classic minimal pair: ele é nervoso (he's a nervous/edgy person — a trait) vs. ele está nervoso (he's nervous right now — a state). With some adjectives the ser/estar choice changes the meaning entirely.
A sopa é de legumes, mas está fria.
The soup is a vegetable soup, but it's cold (right now).
Common Mistakes
❌ Eu estou brasileiro.
Incorrect — nationality is permanent identity: use sou.
✅ Eu sou brasileiro.
I'm Brazilian.
❌ Eu so estudante.
Incorrect — the eu form is sou; só (with accent) means 'only/alone'.
✅ Eu sou estudante.
I'm a student.
❌ Quando eu era pequeno, eu fui muito tímido.
Incorrect — a lasting childhood trait is described with the imperfect era, not the preterite fui.
✅ Quando eu era pequeno, eu era muito tímido.
When I was little, I was very shy.
❌ Se eu seria você, eu pediria desculpas.
Incorrect — 'if I were' uses the imperfect subjunctive fosse, not the conditional.
✅ Se eu fosse você, eu pediria desculpas.
If I were you, I'd apologize.
❌ A reunião está na sala 3.
Incorrect — the location of an event uses ser: a reunião é na sala 3.
✅ A reunião é na sala 3.
The meeting is in room 3.
Key Takeaways
- Ser is the "to be" of identity, essence, origin, permanent qualities, time, and event location.
- Present: sou, és, é, somos, são. Note the accents on é and são.
- The preterite (fui, foi, fomos, foram), the future subjunctive (for, formos, forem), and the imperfect subjunctive (fosse, fôssemos) are shared with ir — context tells them apart.
- Imperfect era / éramos / eram for "used to be" and past description.
- Subjunctive seja / sejamos / sejam; gerúndio sendo; particípio sido.
- For temporary states and object location, use estar, not ser.
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Start learning Portuguese→Related Topics
- Ser for Identity and EssenceA1 — When to use ser in Brazilian Portuguese — identity, profession, origin, material, possession, defining traits, time and dates, and the location of events.
- Ser, Estar, Ficar: The Three 'To Be' VerbsA1 — How Brazilian Portuguese splits the single English verb 'to be' across three verbs — ser for essence, estar for current states, and ficar for change and permanent location.
- EstarA1 — Full conjugation and usage reference for 'estar' (to be) — one of Portuguese's two 'to be' verbs, highly irregular, used for temporary states, location, and the progressive.
- IrA1 — Full conjugation and usage reference for 'ir' (to go) — a highly irregular suppletive verb whose forms come from three different Latin roots, and the engine behind Brazil's everyday spoken future.
- Present Indicative of SerA1 — How to conjugate the verb ser in Brazilian Portuguese and when to use it for identity, origin, time, and the location of events.