Ser (To Be - Essence) — Full Conjugation

Ser is one of the two Portuguese verbs that translate as English to be — the other being estar. While English collapses both meanings into a single word, Portuguese makes a fundamental distinction: ser expresses what something is — its essence, identity, origin, profession, nature, time, or any property felt as inherent or defining — whereas estar expresses how something is right now, its state, condition, or current location (see ser vs estar with adjectives). If you describe someone as é português, you are saying he is Portuguese in essence. If you describe him as está português, you are saying he is looking or behaving Portuguese at this moment (maybe he just got back from Lisbon).

Ser is highly irregular. It descends from two different Latin verbs — esse ("to be") and sedēre ("to sit") — and the modern paradigm borrows forms from both. The result is a suppletive verb whose forms do not always look like they belong to the same word. You will simply have to memorize them: this page lays them all out.

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Present indicative — presente do indicativo

Use this tense for identities, essences, and inherent qualities in the present.

Note the acute accents on és and é — they distinguish these verb forms from the conjunction e ("and"). A missing accent is a spelling error.

Imperfect indicative — pretérito imperfeito

Use this tense for past states, background descriptions, and what used to be.

The era / eram forms are among the most common verb forms in Portuguese — they open fairy tales ("Era uma vez...") and describe every childhood memory.

Preterite indicative — pretérito perfeito simples

Use this tense for completed past actions and bounded past states. These forms are identical to the preterite of ir.

Because fui / foi / fomos / foram are shared with ir, context is everything. Fui ao médico = I went to the doctor; Fui médico = I was a doctor. A preposition (a, para) usually signals ir; a noun, adjective, or participle usually signals ser.

Pluperfect indicative, simple — pretérito mais-que-perfeito simples

The simple pluperfect is a one-word form used mostly in literary writing. In speech, the compound pluperfect (tinha sido) is standard.

The third-person plural foram is identical to the preterite; context disambiguates. Note the circumflex on fôramos: a missing accent here is an error.

Pluperfect indicative, compound — pretérito mais-que-perfeito composto

The everyday way to say had been. Formed with the imperfect of ter plus the past participle sido.

Present perfect — pretérito perfeito composto

Describes an action or state that has been continuing or recurring up to now. Note: tenho sido is used but is noticeably less frequent than tenho estado, because "being something in essence" is rarely a recent repeated phenomenon.

Simple future — futuro do indicativo simples

For future identities or essential qualities. In speech, ir + ser (vou ser) is more common for near-future statements.

The future of ser is also commonly used to express probability or conjecture: Será verdade? = Can it be true? / I wonder if it's true.

Future perfect — futuro perfeito

Will have been. Formed with the future of ter plus sido.

Conditional — condicional

Hypothetical or polite: would be.

Conditional perfect — condicional composto

Would have been. Formed with the conditional of ter plus sido.

Present subjunctive — presente do conjuntivo

Built from the present indicative sou, minus the -u, plus subjunctive endings — but with the characteristic -j- of subjunctives of verbs whose indicative has no -g-. Used after wishes, emotions, doubts, and in many fixed expressions.

The form seja appears in countless fixed expressions: seja o que for (whatever it may be), seja como for (however it may be), ou seja (that is, i.e.), não seja por isso (don't let that stop you).

Imperfect subjunctive — imperfeito do conjuntivo

Used in contrary-to-fact conditions and after past-tense triggers of subjunctive. Built from the -ram of the preterite.

Like the preterite, these forms are shared with ir: Se fosse a ti... can be "if I were you" (ser) or "if I went to you" (ir). Context decides — the former is vastly more common.

Future subjunctive — futuro do conjuntivo

A living tense in Portuguese. Used after se, quando, enquanto, and relative clauses referring to future possibilities.

Once again these forms coincide with ir. Quando fores ao supermercado = when you go to the supermarket (ir); Seja qual for a resposta = whatever the answer is (ser).

Present perfect subjunctive — pretérito perfeito do conjuntivo

Has been, in subjunctive contexts. Formed with the present subjunctive of ter plus sido.

Pluperfect subjunctive — pretérito mais-que-perfeito do conjuntivo

Had been, for contrary-to-fact past.

Future perfect subjunctive — futuro perfeito do conjuntivo

Will have been, in hypothetical future contexts.

Imperative — imperativo

Affirmative:

The tu affirmative sê carries a circumflex — it is a monosyllable and the accent distinguishes it from other homographs. Sê bom! = Be good! Sê tu mesmo = Be yourself.

Negative (identical to the present subjunctive with não):

Personal infinitive — infinitivo pessoal

Used after prepositions and in many impersonal constructions: É importante seres pontual = It is important that you be on time.

Compound personal infinitive — infinitivo pessoal composto

When to use ser

Ser covers the categories where something is identified or classified — the features that define what or who something is:

• Identity and nationality: Sou portuguesa. (I am Portuguese.) Ela é a minha irmã. (She is my sister.)
• Profession: Ele é médico. (He is a doctor.) Notice no article — professions with ser typically drop um / uma.
• Permanent physical and character qualities: Ela é alta e simpática. (She is tall and friendly.)
• Origin and material: Sou de Coimbra. (I am from Coimbra.) A mesa é de madeira. (The table is made of wood.)
• Possession: Este livro é meu. (This book is mine.) A casa é do meu avô. (The house is my grandfather's.)
• Time and dates: São três da tarde. (It is three in the afternoon.) Hoje é quarta-feira. (Today is Wednesday.)
• Impersonal expressions with adjectives: É importante que venhas. (It is important that you come.) These trigger the subjunctive in the subordinate clause.
• Passive voice: A carta foi escrita por ela. (The letter was written by her.) See ser + passive.

Ser vs estar at a glance

For a deeper comparison, see ser vs estar with adjectives.

Example sentences in context

Common mistakes

Key takeaways

• Ser expresses inherent identity, essence, and defining qualities; estar expresses current state and location. Don't conflate them.
• Ser is suppletive: its forms come from two Latin verbs, which is why sou / és / era / fui / seja / fosse look nothing like each other.
• The preterite fui / foste / foi / fomos / foram is identical to the preterite of ir. Context (especially prepositions) tells them apart.
• Age uses ter, not ser: Tenho 25 anos, never sou 25 anos.
• Impersonal expressions like é importante que, é necessário que, é melhor que trigger the subjunctive in the subordinate clause.
• The tu imperative is sê (with circumflex). The negative is não sejas (subjunctive).
• Ser forms the passive voice: A carta foi enviada = the letter was sent. Estar with a participle describes the resulting state: A carta está enviada = the letter is sent (now in the sent state).