Ser Conjugation in Portuguese
ser means “to be” in English, and it is one of the first verbs Portuguese learners meet — it sits at number 1 in VerbFlow’s frequency list for Portuguese verbs. It is the verb of identity, description, origin and time: you use it to say who someone is, what something is like, where someone comes from and what time it is. It shares its pretérito perfeito — fui, foste, foi, fomos, fostes, foram — with ir, so context tells you whether fui means “I was” or “I went”. Learn ser and estar together, because the choice between them is the first decision in almost every Portuguese sentence. This page gives you the complete conjugation of ser — every tense, every person, the gerund and the past participle — with notes, examples, common mistakes and a quiz. Here is the verb in a natural sentence: “Eu sou professor todos os dias.” — “I am a teacher.”
Quick facts
- Infinitive: ser
- English: to be
- Verb type: Irregular -er verb
- Irregular in: presente, pretérito perfeito, pretérito imperfeito, pretérito mais-que-perfeito simples, presente do subjuntivo, pretérito imperfeito do subjuntivo, futuro do subjuntivo, imperativo afirmativo, imperativo negativo
- Gerund: sendo
- Present participle: —
- Past participle: sido
- Auxiliary: ter (all perfect tenses are formed with ter + the past participle)
- Ending: -er verbs; pattern er in the verified tables
Pronunciation
Pronunciation is not listed on this page: the verified tables do not include IPA for ser, so no pronunciation is given rather than an invented one. Learn the spelling of the forms first, and listen to a native speaker for the sounds rather than trusting an invented transcription. The forms below are the ones that matter: once you can read ser in every tense, you can recognise it in speech even before you can pronounce every form perfectly.
Three things to remember about ser
- It is irregular in 9 tense(s): presente, pretérito perfeito, pretérito imperfeito, pretérito mais-que-perfeito simples, presente do subjuntivo, pretérito imperfeito do subjuntivo, futuro do subjuntivo, imperativo afirmativo, imperativo negativo. Learn those forms as a set instead of guessing them from the infinitive, because the stem changes in ways no rule predicts.
- The perfect tenses use ter: the pretérito perfeito composto is formed with ter in the present plus the past participle sido. The tables on this page give the participle in the masculine singular form, exactly as it appears in the verified dump; agreement with the subject is a separate step that depends on the sentence, not on the verb table.
- The gerund is sendo and the past participle is sido: keep both in mind as you read the tables, because the gerund appears in progressive constructions and the past participle appears in every perfect tense. There is no present participle form listed for this verb in the verified tables. If you know those two forms and the present tense, you already know the skeleton of the whole conjugation.
Full conjugation tables
Every form below comes from VerbFlow’s verified conjugation tables for ser. Learn the present tense first, then the pretérito perfeito and the pretérito imperfeito, and add the remaining tenses one at a time.
Present indicative (presente)
| Person | Form |
|---|---|
| eu | sou |
| tu | és |
| ele/ela | é |
| nós | somos |
| vós | sois |
| eles/elas | são |
The present indicative (presente) is used for habits, facts and things happening now. For example: “Eu sou professor todos os dias.” — “I am a teacher”
Pretérito perfeito
| Person | Form |
|---|---|
| eu | fui |
| tu | foste |
| ele/ela | foi |
| nós | fomos |
| vós | fostes |
| eles/elas | foram |
The pretérito perfeito is used for completed actions in the past, especially one finished event. For example: “Eu fui professor ontem.” — “I was a teacher”
Pretérito imperfeito
| Person | Form |
|---|---|
| eu | era |
| tu | eras |
| ele/ela | era |
| nós | éramos |
| vós | éreis |
| eles/elas | eram |
The pretérito imperfeito is used for ongoing or habitual actions in the past, and for background description. For example: “Eu era professor antigamente.” — “I used to be a teacher”
Pretérito mais-que-perfeito simples
| Person | Form |
|---|---|
| eu | fora |
| tu | foras |
| ele/ela | fora |
| nós | fôramos |
| vós | fôreis |
| eles/elas | foram |
The pretérito mais-que-perfeito simples is used for an action completed before another past action; in everyday speech the compound form with tinha is more common. For example: “Eu fora professor antes do jantar.” — “I had been a teacher”
Futuro do presente
| Person | Form |
|---|---|
| eu | serei |
| tu | serás |
| ele/ela | será |
| nós | seremos |
| vós | sereis |
| eles/elas | serão |
The futuro do presente is used for what will happen, for predictions and for promises. For example: “Eu serei professor amanhã.” — “I will be a teacher”
Futuro do pretérito
| Person | Form |
|---|---|
| eu | seria |
| tu | serias |
| ele/ela | seria |
| nós | seríamos |
| vós | seríeis |
| eles/elas | seriam |
The futuro do pretérito is used for what would happen, for polite requests and for hypothetical situations. For example: “Eu seria professor um dia.” — “I would be a teacher”
Pretérito perfeito composto
| Person | Form |
|---|---|
| eu | tenho sido |
| tu | tens sido |
| ele/ela | tem sido |
| nós | temos sido |
| vós | tendes sido |
| eles/elas | têm sido |
The pretérito perfeito composto is used for actions that started in the past and continue, or have been repeated, up to the present. For example: “Ele tem sido professor esta semana.” — “He has been a teacher”
Pretérito mais-que-perfeito composto
| Person | Form |
|---|---|
| eu | tinha sido |
| tu | tinhas sido |
| ele/ela | tinha sido |
| nós | tínhamos sido |
| vós | tínheis sido |
| eles/elas | tinham sido |
The pretérito mais-que-perfeito composto is used for an action completed before another past action. For example: “Eu tinha sido professor antes do jantar.” — “I had been a teacher”
Futuro do presente composto
| Person | Form |
|---|---|
| eu | terei sido |
| tu | terás sido |
| ele/ela | terá sido |
| nós | teremos sido |
| vós | tereis sido |
| eles/elas | terão sido |
The futuro do presente composto is used for what will have happened by a point in the future. For example: “Eu terei sido professor até amanhã.” — “I will have been a teacher”
Futuro do pretérito composto
| Person | Form |
|---|---|
| eu | teria sido |
| tu | terias sido |
| ele/ela | teria sido |
| nós | teríamos sido |
| vós | teríeis sido |
| eles/elas | teriam sido |
The futuro do pretérito composto is used for what would have happened in a different past. For example: “Eu teria sido professor ontem.” — “I would have been a teacher”
Presente do subjuntivo
| Person | Form |
|---|---|
| eu | seja |
| tu | sejas |
| ele/ela | seja |
| nós | sejamos |
| vós | sejais |
| eles/elas | sejam |
The presente do subjuntivo is used for wishes, doubts, emotions and opinions after que. For example: “É importante que eu seja professor.” — “It is important that I be a teacher”
Pretérito imperfeito do subjuntivo
| Person | Form |
|---|---|
| eu | fosse |
| tu | fosses |
| ele/ela | fosse |
| nós | fôssemos |
| vós | fôsseis |
| eles/elas | fossem |
The pretérito imperfeito do subjuntivo is used in the past for wishes and hypotheticals after que, and in se-clauses. For example: “Era importante que eu fosse professor.” — “It was important that I be a teacher”
Futuro do subjuntivo
| Person | Form |
|---|---|
| eu | for |
| tu | fores |
| ele/ela | for |
| nós | formos |
| vós | fordes |
| eles/elas | forem |
The futuro do subjuntivo is used after se and quando for a future possibility, where English would use the present. For example: “Se eu for professor, é bom.” — “If I am a teacher, that is good”
Imperativo (affirmative)
| Person | Form |
|---|---|
| tu | sê |
| ele/ela | seja |
| nós | sejamos |
| vós | sede |
| eles/elas | sejam |
The affirmative imperative is used for direct commands and instructions. For example: “Sê professor!” — “Be a teacher!”
Imperativo (negative)
| Person | Form |
|---|---|
| tu | não sejas |
| ele/ela | não seja |
| nós | não sejamos |
| vós | não sejais |
| eles/elas | não sejam |
The negative imperative is used for prohibitions and negative commands. For example: “Não sejas professor.” — “Do not be a teacher.”
Presente do subjuntivo composto
| Person | Form |
|---|---|
| eu | tenha sido |
| tu | tenhas sido |
| ele/ela | tenha sido |
| nós | tenhamos sido |
| vós | tenhais sido |
| eles/elas | tenham sido |
The presente do subjuntivo composto is used for a completed action in a subordinate clause expressing doubt, wish or emotion. For example: “É importante que eu tenha sido professor.” — “It is important that I have been a teacher”
Pretérito imperfeito do subjuntivo composto
| Person | Form |
|---|---|
| eu | tivesse sido |
| tu | tivesses sido |
| ele/ela | tivesse sido |
| nós | tivéssemos sido |
| vós | tivésseis sido |
| eles/elas | tivessem sido |
The pretérito imperfeito do subjuntivo composto is used for a completed action in a past subordinate clause. For example: “Era importante que eu tivesse sido professor.” — “It was important that I had been a teacher”
Futuro do subjuntivo composto
| Person | Form |
|---|---|
| eu | tiver sido |
| tu | tiveres sido |
| ele/ela | tiver sido |
| nós | tivermos sido |
| vós | tiverdes sido |
| eles/elas | tiverem sido |
The futuro do subjuntivo composto is used after se for a completed future possibility. For example: “Se eu tiver sido professor, é bom.” — “If I have been a teacher, that is good”
Gerund
| Form | Portuguese |
|---|---|
| Gerund | sendo |
The gerund is used for an action happening at the same time as another action, often with estar for the progressive. For example: “Sendo professor, aprendo muito.” — “While being a teacher, I learn a lot.”
Past participle
| Form | Portuguese |
|---|---|
| Past participle | sido |
The past participle is used with an auxiliary to form the perfect tenses, and as an adjective. For example: “Eu tenho sido professor esta semana.” — “I have been a teacher.”
Example sentences
Ten natural sentences with ser, covering different tenses and persons. Say each one aloud, then cover the Portuguese and try to produce it from the English.
- “Eu sou professor todos os dias.” — “I am a teacher”
- “Tu foste professor ontem.” — “You were a teacher”
- “Ele era professor antigamente.” — “He used to be a teacher”
- “Eu serei professor amanhã.” — “I will be a teacher”
- “Tu serias professor um dia.” — “You would be a teacher”
- “Ele tem sido professor esta semana.” — “He has been a teacher”
- “Eu tinha sido professor antes do jantar.” — “I had been a teacher”
- “Tu terás sido professor até amanhã.” — “You will have been a teacher”
- “É importante que eu seja professor.” — “It is important that I be a teacher”
- “Sê professor!” — “Be a teacher!”
Common mistakes
1. Using the infinitive instead of a conjugated form
✗ Wrong: “Eu ser professor.”
✓ Right: “Eu sou professor todos os dias.”
The infinitive ser never takes a subject. After eu you need the conjugated present form sou.
2. Using the wrong person’s form
✗ Wrong: “Eu és professor.”
✓ Right: “Eu sou professor todos os dias.”
és is the tu form, not the eu form. Match the verb to the subject every time: eu goes with sou.
3. Using the present for a finished past action
✗ Wrong: “Eu sou professor ontem.”
✓ Right: “Eu fui professor ontem.”
Ontem points to the past, so the present is wrong here. Use the pretérito perfeito fui for a finished action yesterday.
4. Using the wrong auxiliary in the pretérito perfeito composto
✗ Wrong: “Eu sou sido professor.”
✓ Right: “Eu tenho sido professor esta semana.”
The pretérito perfeito composto of ser is formed with ter plus the past participle sido: the eu form is tenho sido. Check the auxiliary in the table above before you build a perfect tense.
5. Using the indicative after a subjunctive trigger
✗ Wrong: “É importante que eu sou professor.”
✓ Right: “É importante que eu seja professor.”
After é importante que Portuguese needs the subjunctive, so use seja here, not the indicative sou.
6. Using the gerund instead of the past participle in a perfect tense
✗ Wrong: “Eu tenho sendo professor.”
✓ Right: “Eu tenho sido professor esta semana.”
The perfect tenses need the past participle sido, not the gerund sendo. The gerund belongs in progressive constructions, never after an auxiliary in a perfect tense.
Quiz: test yourself
Ten questions on ser. Choose the right form, then check the answer key below.
What is the eu form of ser in the Present indicative (presente)?
- A) és
- B) sou
- C) é
- D) somos
What is the ele/ela form of ser in the Pretérito perfeito?
- A) fui
- B) foste
- C) foi
- D) fomos
What is the nós form of ser in the Pretérito imperfeito?
- A) era
- B) eras
- C) éreis
- D) éramos
What is the tu form of ser in the Futuro do presente?
- A) serás
- B) serei
- C) será
- D) seremos
What is the eu form of ser in the Futuro do pretérito?
- A) serias
- B) seria
- C) seríamos
- D) seríeis
What is the ele/ela form of ser in the Pretérito perfeito composto?
- A) tenho sido
- B) tens sido
- C) tem sido
- D) temos sido
What is the ele/ela form of ser in the Presente do subjuntivo?
- A) sejas
- B) sejamos
- C) sejais
- D) seja
What is the eu form of ser in the Pretérito imperfeito do subjuntivo?
- A) fosse
- B) fosses
- C) fôssemos
- D) fôsseis
What is the gerund of ser?
- A) sido
- B) sendo
- C) ser
- D) sou
What does ser mean in English?
- A) to have
- B) —
- C) to be
- D) —
Answer key
- B) sou — the correct form is sou. The other options are other forms of the same verb.
- C) foi — the correct form is foi. The other options are other forms of the same verb.
- D) éramos — the correct form is éramos. The other options are other forms of the same verb.
- A) serás — the correct form is serás. The other options are other forms of the same verb.
- B) seria — the correct form is seria. The other options are other forms of the same verb.
- C) tem sido — the correct form is tem sido. The other options are other forms of the same verb.
- D) seja — the correct form is seja. The other options are other forms of the same verb.
- A) fosse — the correct form is fosse. The other options are other forms of the same verb.
- B) sendo — the correct form is sendo. The other options are other forms of the same verb.
- C) to be — the correct form is to be. The other options are other forms of the same verb.
Frequently asked questions
What does ser mean in English?
ser means “to be”. It is a core everyday verb, so its present-tense forms are worth learning first.
Is ser regular or irregular?
ser is irregular: it is irregular in presente, pretérito perfeito, pretérito imperfeito, pretérito mais-que-perfeito simples, presente do subjuntivo, pretérito imperfeito do subjuntivo, futuro do subjuntivo, imperativo afirmativo, imperativo negativo. The gerund is sendo and the past participle is sido.
What are the gerund and past participle of ser?
The gerund is sendo — use it with estar for the progressive. The past participle is sido — use it with ter for the perfect tenses, as in tenho sido.
Which auxiliary does ser take in the pretérito perfeito composto?
ser takes ter in the pretérito perfeito composto: the eu form is tenho sido. All seven compound tenses on this page are built with ter plus the past participle sido.
How do I say “I be” in Portuguese?
Say “Eu sou professor todos os dias.” — “I am a teacher” The eu form of the present is sou, and it is the form you will use most often.
Related pages
- Full conjugation of ser — every tense of ser in one place.
- Ser in the pretérito perfeito tense — the full table and usage rules for one tense.
- Ser examples and quiz — more example sentences and practice questions for this verb.
- Portuguese pretérito perfeito tense guide — the full guide to the pretérito perfeito tense in Portuguese.
- Portuguese irregular verbs — every common irregular Portuguese verb, grouped by pattern.
- Ter conjugation — another everyday Portuguese verb.
- Haver conjugation — another everyday Portuguese verb.
- Portuguese verbs — the full hub of Portuguese conjugation pages.
- VerbFlow home — all languages, tools and verb lists.
- Verb Conjugator — practise ser with the interactive tool.
- Conjugation Chart Printer — practise ser with the interactive tool.
- Tense Finder — practise ser with the interactive tool.