A Portuguese passive sentence with an explicit agent always has the same frame: past participle + por + agent. Learn that frame, learn the obligatory contractions of por with the definite article, and you have almost everything you need. The harder skill is knowing when to include the agent at all — because in good Portuguese prose, most passives leave the agent out entirely. This page covers the full mechanics of the por phrase, the four types of agents you are likely to meet, and the subtle archaism of de as an alternative marker that you will still see in literary texts.
The basic frame
Subject + ser (conjugated) + past participle + por + agent.
O relatório foi assinado pelo director.
The report was signed by the director.
A decisão foi tomada pela equipa.
The decision was taken by the team.
Os livros foram escritos pelos alunos.
The books were written by the students.
As fotografias foram tiradas pelas crianças.
The photos were taken by the children.
The participle agrees with the subject in gender and number. The preposition por does all the agent-marking work.
Obligatory contractions
Por fuses with the definite article. This is not optional — writing por o is a spelling error, just as writing de o instead of do would be.
| por + | Contraction | Example |
|---|---|---|
| o (masc. sing.) | pelo | foi escrito pelo autor |
| a (fem. sing.) | pela | foi escrita pela autora |
| os (masc. pl.) | pelos | foi adorado pelos leitores |
| as (fem. pl.) | pelas | foi lida pelas alunas |
With indefinite articles (um, uma, uns, umas), no contraction occurs. Por and the article stay separate.
O quadro foi pintado por um amigo meu.
The painting was painted by a friend of mine. (indefinite — no contraction)
A proposta foi apresentada por uma deputada.
The proposal was presented by a (female) MP. (indefinite — no contraction)
With bare names, pronouns, and nouns without articles, again no contraction.
A carta foi escrita por Maria.
The letter was written by Maria. (bare name)
Foi feito por mim.
It was done by me. (pronoun)
A cidade foi fundada por colonos romanos.
The city was founded by Roman colonists. (no article)
Four types of agents
1. A specific person
By far the most common. A named individual or pronoun.
O romance foi escrito por José Saramago em 1982.
The novel was written by José Saramago in 1982.
A peça foi dirigida por ela durante três anos.
The play was directed by her for three years.
Este prato foi preparado pelo chef em pessoa.
This dish was prepared by the chef in person.
2. A group or collective
Plural agents — teams, organizations, groups of people. Watch the contraction with plural articles.
A proposta foi aprovada pelos deputados por unanimidade.
The motion was approved by MPs unanimously.
A exposição foi inaugurada pelas autoridades locais.
The exhibition was opened by the local authorities.
O prémio foi atribuído por um júri internacional.
The prize was awarded by an international jury.
3. An institution
Companies, organizations, government bodies. The article is usually present, so contraction applies.
A nova lei foi publicada pelo Governo na quinta-feira.
The new law was published by the government on Thursday.
O banco foi multado pela autoridade reguladora.
The bank was fined by the regulatory authority.
O edifício foi restaurado pela Câmara Municipal de Lisboa.
The building was restored by Lisbon City Council.
4. An abstract cause or natural force
Portuguese readily marks abstract causes with por — emotions, phenomena, forces. This is one area where English "by" feels awkward but Portuguese por is completely natural.
A aldeia foi destruída pelo terramoto.
The village was destroyed by the earthquake.
Ela foi abalada pela notícia.
She was shaken by the news.
O projecto foi inspirado pela arquitectura tradicional.
The project was inspired by traditional architecture.
A viagem foi adiada pelo mau tempo.
The trip was postponed because of (lit. by) the bad weather.
Notice the last example: por often stretches to mean "because of" when the cause is a non-agentive force, blurring into the domain of cause-and-reason marking.
When to include the agent — and when to drop it
In good Portuguese prose, most passives have no explicit agent. The point of the passive is often exactly to suppress the agent: either it is unknown, or it is irrelevant, or the focus should be on the patient.
Include the agent when:
- the agent is new or relevant information
- you want to emphasize who did the action
- naming the agent adds concrete content to the sentence
O livro foi traduzido pela Ana Falcão, que é especialista em Fernando Pessoa.
The book was translated by Ana Falcão, who is a Pessoa specialist. (agent is informative)
Drop the agent when:
- the agent is unknown or guessable
- the agent is a generic "people" and would add nothing
- the agent is already obvious from context
A igreja foi construída no século XVIII.
The church was built in the 18th century. (no agent — obviously a mason or builder, not worth naming)
O passaporte foi-lhe roubado no metro.
His passport was stolen from him on the metro. (agent unknown)
O novo museu foi inaugurado no domingo.
The new museum was opened on Sunday. (agent inferable, irrelevant to the news)
A sentence like o livro foi escrito por alguém ("the book was written by someone") is grammatical but stilted — you should simply say o livro foi escrito and let the reader infer "someone."
Register cline: de as an agent marker
In modern European Portuguese, the agent preposition is almost always por. But you will still meet de as an agent marker in older texts, in literary prose, and with certain verbs of emotion or attitude. This is an archaism with deep roots in Romance grammar — Latin had ab for the passive agent, and Old Portuguese inherited both por and de as competing translations.
With certain verbs of emotion, attitude, or knowledge, de can still appear as a slightly elevated alternative to por:
É respeitado por todos.
He is respected by everyone. (modern neutral)
Era amada de quantos a conheciam.
She was loved by all who knew her. (literary, deliberately archaic flavour)
Era amada por todos os que a conheciam.
She was loved by everyone who knew her. (modern neutral)
In contemporary journalistic or conversational Portuguese, use por. Use de only if you are deliberately aiming at a literary register — for example, in a poem, a formal eulogy, or a historical novel. The forms below are genuine literary Portuguese but would sound odd in a news report:
Foi acompanhado de um silêncio profundo.
It was accompanied by a deep silence. (literary — de is the traditional choice with 'acompanhar')
A handful of verbs prefer de even in modern usage — notably acompanhado de (accompanied by), composto de (composed of), and cercado de (surrounded by, especially with concrete walls or buildings, alongside the equally valid cercado por). These border on adjectival uses rather than true passives.
O jardim é cercado de muros altos.
The garden is surrounded by high walls.
O livro é composto de dez capítulos.
The book is composed of ten chapters.
Spanish-speaker warning: don't import de
Spanish has exactly the same old Romance alternation, and older Spanish texts use de liberally as an agent marker (amado de todos, temido de sus enemigos). Modern Spanish mostly prefers por too, but the literary tradition of de is stronger there than in Portuguese. Spanish speakers learning Portuguese should default to por and treat de as a deliberately archaic or literary flavour, not a living option.
❌ É amado de todos os colegas.
Marked as archaic / literary — sounds old-fashioned in modern Portuguese. Prefer 'por'.
✅ É amado por todos os colegas.
He is loved by all his colleagues. (modern neutral)
Agent-like phrases that look like passives
Portuguese uses por in several other functions that can be confused with the passive agent. Keep them distinct.
Por = "because of" / "for the sake of"
Fizemos isto por ti.
We did this for you / for your sake. (benefactive — not passive)
Foi castigado por ter mentido.
He was punished for having lied. (cause, not agent)
Por = "through" / "via" / "by means of"
Mandei-te a fotografia por email.
I sent you the photo by email. (means)
Fomos de Lisboa ao Porto por Coimbra.
We went from Lisbon to Porto via Coimbra. (route)
Por = "per" (distributive)
Duas vezes por semana.
Twice a week.
None of these are passive agents. The passive agent always answers the question "by whom (or by what force) was this action performed?" — if the answer is "because," "through," or "per," you are in a different grammatical territory.
Compound tenses and the agent
The agent phrase sits after the participle, regardless of how many auxiliaries are stacked. Por + agent comes at the end of the verb complex, not before.
O edifício tinha sido inaugurado pelo presidente em 2005.
The building had been opened by the president in 2005. (pluperfect passive)
A proposta terá sido rejeitada pela comissão até amanhã.
The proposal will have been rejected by the commission by tomorrow. (future perfect passive)
A mensagem tem sido repetida por todos os partidos.
The message has been repeated by all parties. (present perfect passive)
Note the invariant sido (after ter) and the agreeing main participle — see the past participle agreement page for the full explanation.
Common mistakes
❌ O livro foi escrito para Saramago.
Incorrect — 'para' expresses purpose or beneficiary ('for Saramago'), not the agent. Use 'por' for the passive agent.
✅ O livro foi escrito por Saramago.
The book was written by Saramago.
Por and para are distinct prepositions with distinct functions. For a passive agent, it is always por. Confusing them — especially easy for Spanish speakers who often mentally translate between cognates — is the most common error here.
❌ A decisão foi tomada por o presidente.
Incorrect — 'por + o' obligatorily contracts to 'pelo'.
✅ A decisão foi tomada pelo presidente.
The decision was made by the president.
The contraction rule is not optional; forgetting it is a spelling error.
❌ O prémio foi atribuído pelo um júri internacional.
Incorrect — 'pelo um' mixes the contracted definite with an indefinite article, which is impossible. Use 'por um' (no contraction with 'um').
✅ O prémio foi atribuído por um júri internacional.
The prize was awarded by an international jury.
No contraction with indefinite articles.
❌ Ele é respeitado de todos os colegas.
Borderline — understandable but sounds literary or old-fashioned in everyday Portuguese. Modern neutral register prefers 'por'.
✅ Ele é respeitado por todos os colegas.
He is respected by all his colleagues.
Use de only for clearly literary effect or in the fixed expressions (acompanhado de, composto de, cercado de).
❌ A carta foi escrita pelo mim.
Incorrect — 'pelo' is 'por + the definite article o'; with a pronoun like 'mim', use bare 'por'.
✅ A carta foi escrita por mim.
The letter was written by me.
Never contract por with a pronoun.
❌ A casa foi construída pela 1920.
Incorrect — for time expressions, use 'em', not 'por'.
✅ A casa foi construída em 1920.
The house was built in 1920.
Por is not a time preposition in this sense; it marks the agent, not the year.
Key takeaways
- The agent in a Portuguese passive is marked with por. Never para. Rarely, and only in literary register, de.
- Por contracts obligatorily with the definite articles o, a, os, as to form pelo, pela, pelos, pelas.
- With indefinite articles (um, uma), pronouns, and bare nouns, no contraction.
- Most passives in good Portuguese prose drop the agent entirely. Include it only when it adds information.
- Four common agent types: a specific person, a group, an institution, an abstract cause or force.
- De as an agent marker is a literary archaism, alive in fixed phrases (acompanhado de, composto de, cercado de) and in deliberately elevated prose.
- Distinguish the passive por from por in its many other roles: cause, means, route, distributive. Only the "by whom/by what" meaning is the passive agent.
Related Topics
- Ser + Past Participle (Analytic Passive)B1 — The Portuguese analytic passive — ser + past participle + (por + agent). The most explicit passive construction, with mandatory participle agreement and the por contractions (pelo, pela, pelos, pelas).
- Active to Passive: Step-by-Step TransformationB1 — How to turn any active Portuguese sentence into its passive counterpart — a clean four-step recipe that works across every tense.
- Impersonal SeB1 — How European Portuguese uses 'se' to make generic, subjectless statements — the equivalent of English 'one does X' or 'you do X' in the impersonal sense.
- Ficar + Past Participle: The Resultative PassiveB2 — How 'ficar + past participle' expresses a resulting state after a change — the distinct third voice alongside ser (event) and estar (state) that European Portuguese uses productively.
- Past Participle AgreementB1 — When past participles agree in gender and number, and when they don't — the sharp split between ter (invariant) and ser / estar / ficar / adjectival use (full agreement).