Certo / Determinado: 'Certain' Determiner | Portuguese (Brazil) Grammar

Brazilian Portuguese has a pair of vague placeholder determiners that translate the English "a certain" — the deliberately unspecific a certain person, certain situations. The everyday word is certo; its more formal twin is determinado. The catch — and it is a beautiful one — is that certo completely changes meaning depending on where it sits relative to the noun: before the noun it means "a certain / some"; after the noun it means "correct, right." Position is everything here, and getting it wrong produces real confusion. This page maps both words and the positional flip.

Certo before the noun = "a certain / some"

When certo/certa/certos/certas comes before the noun, it is an indefinite determiner: it points to a specific but unnamed referent the speaker has in mind but chooses not to identify — exactly English "a certain." It agrees in gender and number with the noun:

Certo dia, ela simplesmente desapareceu.

One day / A certain day, she simply vanished. (certo before 'dia')

Recebi a notícia de certa pessoa.

I got the news from a certain person. (deliberately unnamed)

Certas pessoas nunca aprendem.

Certain people never learn. (certas, fem. pl.)

Em certos casos, vale a pena insistir.

In certain cases, it's worth insisting. (certos, masc. pl.)

The flavor is intentionally fuzzy — like English "a certain," it implies the speaker could be specific but isn't being. Note that prenominal certo in this sense normally takes no article: certo dia, not um certo dia — though, as with outro, colloquial BR does say um certo quite freely.

Há um certo charme nessa bagunça toda.

There's a certain charm to all this mess. (colloquial 'um certo' — very common)

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Position decides meaning for certo: before the noun = "a certain / some" (certa pessoa); after the noun = "correct" (a resposta certa). Same word, two unrelated meanings.

Certo after the noun = "correct, right"

Move certo to its normal adjective slot after the noun, and the placeholder meaning evaporates. Now it means "correct, right, the proper one":

Essa é a resposta certa.

That's the correct answer. (certa AFTER 'resposta' = correct)

Chegamos na hora certa.

We arrived at the right time. (a hora certa = the right/correct time)

Será que tomei a decisão certa?

I wonder if I made the right decision.

Put the two side by side and the positional logic is stark: certa pessoa = "a certain (unnamed) person"; a pessoa certa = "the right person." This is not a subtle nuance — it is two different meanings selected purely by word order, and it is one of the cleanest illustrations in the language of how Portuguese loads meaning onto adjective placement.

Você é a pessoa certa para o cargo.

You're the right person for the position. (postnominal = correct/suitable)

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Quick test: if you can swap in "correct/right" and it works, the word goes after the noun (a conta certa). If you mean "some unspecified," it goes before (certa conta).

Determinado — the formal twin

Determinado/determinada/determinados/determinadas is the more formal, more written synonym of prenominal certo. It means "a certain / a specific / a given" and is common in academic, legal, and journalistic prose where certo might feel too colloquial:

Em determinada situação, a regra muda.

In a certain/given situation, the rule changes. (formal/academic)

A lei só se aplica a determinados casos.

The law applies only to certain (specific) cases.

Determinadas decisões cabem apenas ao diretor.

Certain decisions fall solely to the director. (formal register)

Crucially, determinado does not have the positional double life that certo has. Placed after a noun it reads as the past participle of determinar ("determined / fixed"), e.g. o prazo determinado = "the set deadline" — a related but distinct meaning. So determinado is the safe choice when you want "a certain" without any risk of the "correct" reading: it lives prenominally and stays formal.

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Determinado = the formal/academic version of prenominal certo ("a given / a specific"). Reach for it in writing; use certo in speech.

Comparison with English

English handles all of this with the fixed phrase "a certain" plus, separately, the adjective "correct/right." The word certain in English never inflects and never changes meaning by position. Portuguese, by contrast, (1) inflects certo for gender and number, and (2) uses position as a meaning switch — the very same form certo is the placeholder "a certain" in front and the adjective "correct" behind. There is no English parallel for one word doing both jobs by reordering. For the formal "a certain," English has no special word at all; it just says "a certain" or "a given," which is where Portuguese determinado comes in. The practical danger for English speakers is producing a resposta certo (no agreement) or, worse, putting the placeholder certo after the noun and accidentally saying "correct" when you meant "a certain."

Common Mistakes

❌ Quero a pessoa certa pro trabalho — não importa quem.

Contradictory — postnominal 'certa' means 'the right/correct person', not 'some unspecified one'.

✅ Quero certa pessoa pro trabalho — não importa quem.

I want a certain (specific kind of) person for the job. (prenominal = 'a certain')

❌ Essa é a certa resposta.

Wrong position — 'correct answer' needs 'certa' AFTER the noun.

✅ Essa é a resposta certa.

That's the correct answer.

❌ Em certo situações, a regra muda.

No agreement — 'situações' is feminine plural, so 'certas'.

✅ Em certas situações, a regra muda.

In certain situations, the rule changes.

❌ A lei se aplica a determinado casos.

No agreement — masculine plural needs 'determinados'.

✅ A lei se aplica a determinados casos.

The law applies to certain cases.

Key Takeaways

certo before the noun = "a certain / some" (certa pessoa); after the noun = "correct / right" (a resposta certa). Position is the meaning switch.
Prenominal certo normally takes no article (certo dia), though colloquial um certo is common.
determinado is the formal/academic synonym of prenominal certo ("a given / a specific") and stays in front of the noun.
Both agree in gender and number with the noun — certas situações, determinados casos.
English "a certain" never inflects and never flips by position; Portuguese does both.

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