Contraction Errors | Portuguese (Brazil) Grammar

In English, prepositions and articles stay as separate words: "of the", "in the", "to the". Brazilian Portuguese fuses them, and the fusion is obligatory — not a stylistic shortcut you can take or leave. Writing "de a casa" instead of "da casa" is not informal or sloppy; it is simply wrong, the way "to-day without the hyphen" used to be wrong. This page covers the contraction errors English speakers make: failing to contract, contracting wrongly, missing the crase accent, and over-contracting before infinitives.

Error 1: Failing to contract (the #1 error)

English keeps preposition + article apart, so learners write them apart in Portuguese too. But the four big prepositions — de, em, a, por — must merge with a following definite article (o, a, os, as).

Preposition + article	❌ Wrong (uncontracted)	✅ Required contraction
de + o / a / os / as	de o, de a	do, da, dos, das
em + o / a / os / as	em o, em a	no, na, nos, nas
a + o / a / os / as	a o, a a	ao, à, aos, às
por + o / a / os / as	por o, por a	pelo, pela, pelos, pelas

❌ O carro de o meu pai está em a garagem.

Incorrect — 'de o' and 'em a' must contract

✅ O carro do meu pai está na garagem.

My father's car is in the garage.

❌ Eu vou a o cinema por a tarde.

Incorrect — 'a o' and 'por a' must contract

✅ Eu vou ao cinema pela tarde.

I'm going to the cinema in the afternoon.

This also applies to the indefinite articles and to demonstratives and pronouns: em + um → num, de + um → dum, em + ele → nele, de + ele → dele, em + isso → nisso, de + isso → disso.

❌ Eu moro em um apartamento perto de aqui.

Marginal — 'num' is strongly preferred; 'daqui' is required

✅ Eu moro num apartamento perto daqui.

I live in an apartment near here.

✅ Eu gosto muito disso.

I really like that. (de + isso = disso)

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Contraction in Brazilian Portuguese is grammatical glue, not slang. If you ever write "de o", "em a", "a o", or "por a" as two words, it's an error — fuse them every time.

Error 2: The wrong contraction

Once learners know contractions exist, they sometimes pick the wrong one — usually confusing the de- and em- families, or forgetting that "por" becomes the irregular "pelo/pela".

❌ Obrigado por o presente.

Incorrect — 'por o' contracts irregularly

✅ Obrigado pelo presente.

Thanks for the present.

❌ Ela passou pela porta e entrou no a sala.

Incorrect — 'no a' is a garbled double contraction; should be 'na sala'

✅ Ela passou pela porta e entrou na sala.

She went through the door and into the room.

The trap with por is that its contraction (pelo/pela/pelos/pelas) doesn't look like "por" at all — it comes from the old form "per". Memorize it as its own item, separate from the regular do/no/ao patterns.

Error 3: The missing crase (à)

The crase is the accent on à, marking the contraction of the preposition a + the feminine article a (a + a = à). English has no equivalent — "to the beach" gives no hint that anything should merge — so learners write "a praia" and lose both the contraction and the accent.

❌ Eu vou a praia no domingo.

Incorrect — 'ir a' + feminine 'a praia' requires the crase à

✅ Eu vou à praia no domingo.

I'm going to the beach on Sunday.

❌ Ela se referiu a aquela reunião.

Incorrect — a + aquela contracts to àquela

✅ Ela se referiu àquela reunião.

She referred to that meeting.

The reliable test: replace the feminine noun with a masculine one. If "a" becomes "ao", then the feminine version needs the crase "à". "Vou ao cinema" (masculine) → "Vou à praia" (feminine). If the masculine swap gives just "a" (no contraction), then no crase: "Vou a pé" → no article, so "❌à pé" is wrong.

✅ Nós fomos ao mercado e depois à farmácia.

We went to the market and then to the pharmacy. (ao masc., à fem.)

❌ Aos poucos ela foi à pé até a escola.

Incorrect — 'a pé' has no article, so no crase

✅ Aos poucos ela foi a pé até a escola.

Little by little she walked to school.

The crase is also obligatory in time expressions with feminine hours and in many fixed phrases: às três horas (at three o'clock), à noite (at night), à direita (on the right).

✅ A reunião começa às nove da manhã.

The meeting starts at nine in the morning.

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Crase test: swap the feminine noun for a masculine one. If you'd say "ao", use "à". If you'd just say "a", no crase. This single test resolves almost every crase decision.

Error 4: Over-contracting before an infinitive

Knowing that "de + o" must contract, learners sometimes contract the preposition with the subject of a following infinitive — but here the "o filme" is the subject of "começar", and prescriptive grammar says the preposition should not contract with it. This is genuinely debated, so be honest about it.

❌ Antes do filme começar, vamos comprar pipoca.

Widely said, but prescriptively the preposition shouldn't contract with the infinitive's subject

✅ Antes de o filme começar, vamos comprar pipoca.

Before the movie starts, let's buy popcorn.

✅ Depois de a chuva passar, saímos.

After the rain passes, we'll go out. (prescriptive form)

Here is the honest picture: in formal writing and on language exams, keep them separate — "antes de o filme começar" — because "o filme" is the subject of "começar", not the object of "de". In everyday Brazilian speech and informal writing, "antes do filme começar" is overwhelmingly common and most Brazilians don't notice anything wrong with it. So this is the mirror image of errors 1–3: there, contracting is mandatory; here, not contracting is the careful choice. Match the register: contract freely in speech, separate them in formal prose.

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The contraction rule has one exception worth knowing: when the article-like word is actually the subject of a following infinitive ("o filme começar"), formal grammar keeps the preposition separate ("antes de o filme começar"). In speech, contracting it is normal.

Common Mistakes recap

❌ Eu peguei o presente de a Maria e coloquei em a mesa.

Two failures to contract: 'de a' → da, 'em a' → na

✅ Eu peguei o presente da Maria e coloquei na mesa.

I took Maria's present and put it on the table.

❌ Vou a aula de manhã e a academia a tarde.

Crase missing on 'à academia' and 'à tarde'

✅ Vou à aula de manhã e à academia à tarde.

I go to class in the morning and to the gym in the afternoon.

❌ Eu não sei nada a respeito de isso.

'de + isso' must contract to 'disso'

✅ Eu não sei nada a respeito disso.

I don't know anything about that.

Key takeaways

Contraction of de/em/a/por + article is mandatory, not optional. "❌de o" → do, "❌em a" → na, "❌a o" → ao, "❌por a" → pela.
por contracts irregularly to pelo/pela/pelos/pelas — memorize it separately.
The crase à (a + feminine a) is easy to drop because English has nothing like it: "vou à praia", not "❌vou a praia". Use the "ao" swap test.
Contractions also apply to um (num/dum), pronouns (nele/dele), and demonstratives (disso/nisso/àquela).
The one place you shouldn't contract (formally) is before the subject of an infinitive: "antes de o filme começar" — though "antes do filme começar" is normal in speech.

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