Ambos is the Portuguese word for both. It is always plural, agrees in gender, and has a distinctive placement rule: it sits before the definite article, producing the unusual-looking pattern ambos os / ambas as. In spoken PT-PT, os dois and as duas are in fact the everyday alternatives — more colloquial and slightly more frequent than ambos. This page covers the forms, the fixed article pattern, the comparison with os dois, and the preposition-plus-ambos combinations that recur in everyday speech.
Forms
Ambos has only two forms — a masculine and a feminine — because it is inherently plural. There is no singular *ambo.
| Masculine plural | Feminine plural |
|---|---|
| ambos | ambas |
Ambos os meus irmãos vivem em Lisboa.
Both my brothers live in Lisbon.
Ambas as minhas irmãs são médicas.
Both my sisters are doctors.
Li ambos os livros numa semana.
I read both books in a week.
Ambas as portas estavam fechadas.
Both doors were closed.
Gender agreement follows the rule of the noun being referred to. Mixed groups default to masculine: ambos os pais (both parents — literally both fathers, but conventionally parents of either sex).
The article rule — ambos os / ambas as
This is the distinctive feature of ambos that catches learners. When ambos / ambas modifies a noun, the definite article sits between ambos and the noun:
ambos + os + noun
ambas + as + noun
Ambos os alunos chegaram atrasados.
Both students arrived late.
Ambas as respostas estão certas.
Both answers are correct.
Ambos os países têm economias fortes.
Both countries have strong economies.
Ambas as cidades são lindas.
Both cities are beautiful.
Forgetting the article — *ambos irmãos, *ambas irmãs — produces a phrase that sounds immediately off to a Portuguese ear. This is one of the most reliable errors English speakers make, because English just says both brothers with no article in between. The article is obligatory whenever ambos modifies a noun directly.
With possessives — ambos os meus, ambas as minhas
When a possessive is also present, it slots in between the article and the noun — not between ambos and the article. The fixed order is:
ambos + os + possessive + noun
ambas + as + possessive + noun
Ambas as minhas avós nasceram no Alentejo.
Both my grandmothers were born in the Alentejo.
Ambos os nossos filhos estudam na universidade.
Both our children are at university.
Ambas as tuas propostas fazem sentido.
Both your proposals make sense.
Do not skip the article — *ambos meus irmãos is ungrammatical. The chain is always ambos + article + possessive + noun.
Ambos without a noun — pronominal use
When the referent is already clear from context, ambos can stand alone as a pronoun:
Ambos vieram à festa.
Both came to the party.
Ambas me telefonaram ontem à noite.
Both (of them, fem.) called me last night.
Escolhi entre dois candidatos — ambos tinham experiência.
I chose between two candidates — both had experience.
Ambos concordámos com a decisão.
We both agreed with the decision.
Notice the last example: when ambos is the subject, the verb goes into first person plural (concordámos) because it refers to nós — "we both." The verb agrees with the understood pronoun, not with ambos itself.
Note also the acute accent on concordámos (first person plural preterite) — a PT-PT feature that distinguishes the preterite (concordámos = we agreed) from the present (concordamos = we agree). Brazilian Portuguese merges both into concordamos.
Ambos with prepositions
Ambos combines freely with prepositions. No contractions apply (since ambos does not begin with a vowel-initial article).
Falei com ambos os meus pais.
I talked with both my parents.
Dei o livro a ambos os alunos.
I gave the book to both students.
Em ambos os casos, a resposta é a mesma.
In both cases, the answer is the same.
De ambos os lados da rua há árvores.
On both sides of the street there are trees.
Por ambos os motivos, decidi adiar a viagem.
For both reasons, I decided to postpone the trip.
Para ambas as equipas, foi um jogo difícil.
For both teams, it was a difficult match.
You will note that em + ambos does not contract to *nambos — em only contracts with the articles o/a/os/as and a few pronouns, not with ambos. Keep them apart: em ambos os casos.
Ambos vs. os dois / as duas — register and frequency
Here is the practical truth about ambos in spoken PT-PT: many native speakers prefer os dois / as duas in everyday speech. Ambos sounds slightly more formal, more literary, more careful — and in fact Brazilian Portuguese leans even more heavily on os dois. Both forms are grammatical and understood, but the register differs.
| Form | Register | Example |
|---|---|---|
| ambos os / ambas as | Neutral to slightly formal; more common in writing | ambos os irmãos |
| os dois / as duas | Colloquial, very common in spoken PT-PT | os dois irmãos |
Ambos os irmãos estudam em Coimbra.
Both brothers study in Coimbra. (neutral/formal)
Os dois irmãos estudam em Coimbra.
Both brothers study in Coimbra. / The two brothers study in Coimbra. (colloquial)
Ambas as amigas chegaram cedo.
Both friends (fem.) arrived early. (more formal)
As duas amigas chegaram cedo.
Both friends / the two friends arrived early. (colloquial)
The two are effectively interchangeable in meaning. Which to use depends on how formal the context is. In a business email, ambos os candidatos fits perfectly. In a conversation at a café, os dois candidatos would sound more natural.
The Spanish cognate
Spanish has the same word — ambos/ambas — but uses it differently. Spanish ambos does not take the article:
- Spanish: ambos hermanos (no article)
- Portuguese: ambos os irmãos (with article, obligatory)
Spanish speakers transferring to Portuguese reliably drop the article, producing *ambos irmãos. This is wrong in PT-PT. The article is mandatory.
❌ Ambos irmãos chegaram.
Missing article — correct PT-PT is 'ambos os irmãos'.
✅ Ambos os irmãos chegaram.
Both brothers arrived.
Idiomatic expressions with ambos
Ambos appears in several set expressions worth memorising.
De ambos os lados há argumentos válidos.
On both sides there are valid arguments.
Em ambos os sentidos da palavra.
In both senses of the word.
Para bem de ambos, é melhor conversarmos.
For the good of both, it's better if we talk.
Ambos os lados da moeda.
Both sides of the coin.
Em ambos os casos, ganhas.
In either case / in both cases, you win.
The expression em ambos os casos is especially frequent in formal and semi-formal writing — essays, reports, arguments.
Ambos vs. cada um / cada uma — subtle difference
Sometimes English each and both overlap. Portuguese keeps them distinct:
- Ambos → both together, collectively
- Cada um / cada uma → each one, separately
Ambos os irmãos têm um carro.
Both brothers have a car. (ambiguous — could mean one shared car or one each)
Cada um dos irmãos tem um carro.
Each of the brothers has a car. (one car per brother, unambiguously)
Ambos receberam o prémio.
Both received the prize. (one prize shared, or they both got prizes — context-dependent)
Cada um recebeu o seu prémio.
Each one received his own prize. (one each, unambiguous)
When you need to stress "one each, individually," cada um / cada uma is the sharper choice. When you mean "the two of them, together or collectively," reach for ambos or os dois.
Register notes
- (formal / written) Ambos os / ambas as + noun is neutral to slightly formal. Very common in journalism, essays, and careful speech.
- (neutral / colloquial) Os dois / as duas + noun is the everyday spoken form.
- (literary) Ambos as a bare pronoun (ambos concordaram) has a slightly literary flavour when used alone; the spoken version often prefers os dois or nós os dois / elas as duas.
- (archaic / rare) Older texts sometimes use ambos de dois (both of the two). Avoid in modern Portuguese.
Common Mistakes
❌ Ambos irmãos vieram.
Missing article — PT-PT requires 'ambos os irmãos'.
✅ Ambos os irmãos vieram.
Both brothers came.
❌ Ambos as amigas vieram.
Gender mismatch — 'amigas' is feminine, so 'ambas as amigas'.
✅ Ambas as amigas vieram.
Both friends (fem.) came.
❌ Ambo livro é bom.
No singular form — 'ambos' is always plural.
✅ Ambos os livros são bons.
Both books are good.
❌ Ambos os meus todos irmãos.
Nonsensical stacking — 'todos' duplicates 'ambos'.
✅ Ambos os meus irmãos.
Both my brothers.
❌ Os meus ambos amigos.
Wrong order — 'ambos' must come before the article.
✅ Ambos os meus amigos.
Both my friends.
❌ Eu falei com ambos irmãos ontem.
Missing article — 'com ambos os irmãos'.
✅ Falei com ambos os irmãos ontem.
I talked with both brothers yesterday.
❌ Ambos os dois estudantes passaram.
Redundant — 'ambos' and 'os dois' mean the same. Pick one.
✅ Ambos os estudantes passaram.
Both students passed.
✅ Os dois estudantes passaram.
The two / both students passed.
Key Takeaways
- Ambos has only plural forms: ambos (masculine), ambas (feminine). No singular exists.
- Article is obligatory between ambos and the noun: ambos os irmãos, ambas as irmãs.
- With possessives: ambos os meus irmãos — ambos + article + possessive + noun, in that fixed order.
- As a pronoun (no noun), ambos / ambas stands alone: ambos vieram, ambas concordaram.
- Verb agreement with ambos as subject follows the implied subject — typically first person plural when ambos means "we both": ambos concordámos.
- Colloquial alternative: os dois / as duas is the everyday spoken form. Interchangeable in meaning, less formal.
- Spanish cognate ambos does NOT take the article — Spanish speakers must add the article when switching to Portuguese.
- Distinguish from cada um / cada uma — ambos = collectively, both together; cada um = individually, each one separately.
- Common idioms: de ambos os lados, em ambos os casos, em ambos os sentidos.
- Do not stack with todos or os dois — these mean the same thing; choose one.
Related Topics
- Determiners in Portuguese: An OverviewA1 — What determiners are, the families of determiners in European Portuguese, and how they combine with nouns — a map of the group.
- Indefinite Determiners: algum, nenhum, qualquer, cada, todo, vário, certoA2 — A guided tour of the Portuguese indefinite determiners — words that quantify or identify without being definite: algum, nenhum, qualquer, cada, todo, vário, certo, muito, pouco, outro, mesmo, tanto, and the todo/tudo distinction.
- Todo vs. Tudo: Variable vs. InvariableA2 — Distinguishing the variable determiner todo/toda/todos/todas from the invariable pronoun tudo — one of the most reliable stumbling blocks for English and Spanish speakers learning Portuguese.
- Cardinal and Ordinal Numbers as DeterminersA2 — Using cardinals (um, dois, três) and ordinals (primeiro, segundo, terceiro) as determiners in European Portuguese — with gender agreement, the 'e' in compound numerals, and the critical PT-PT vs. Brazilian difference in bilião / bilhão.
- The Definite Article: Forms and Basic UsesA1 — The four forms of the Portuguese definite article (o, a, os, as) and the contexts where European Portuguese requires it — including several where English leaves it out.