Spelling Differences

The single biggest thing to know about PT-PT/BR spelling is that, since the Acordo Ortográfico de 1990 (usually called AO90 or just o acordo), the two varieties now share about 98% of their orthography. The reform, which Portugal implemented in 2008–2015 and Brazil in 2009–2012, was specifically designed to unify the written standard so that books, software, legal texts, and educational materials could be published in a single spelling for the whole Portuguese-speaking world. For the most part, it worked.

But the remaining 2% matters. It is uneven across word types, politically charged in Portugal (where a substantial minority of writers continue to reject the reform), and full of small gotchas that betray the origin of a text instantly. This page maps out what the reform changed, what it didn't, and what still divides PT-PT from BR in writing today — including the pre-reform forms you will still see in older books, newspapers, and websites. All spellings in this guide follow AO90 unless explicitly noted.

The Acordo Ortográfico in one paragraph

The AO90 was a treaty signed in 1990 by all eight Portuguese-speaking countries (Portugal, Brazil, Angola, Mozambique, Cape Verde, Guinea-Bissau, São Tomé and Príncipe, and later East Timor). Its core moves: (1) remove silent consonants in words where they had fallen out of pronunciation (acção → ação, Egipto → Egito), (2) standardise hyphenation, (3) align accent rules, and (4) merge variant accent placements (pára → para, pêra → pera). Portugal ratified implementation in 2008 with a transition period ending in 2015; Brazil began in 2009 with a transition ending in 2012. After these dates, the post-reform spelling is the only officially valid one in both countries, though Portuguese usage has been uneven.

1. The "silent consonant" words — where PT-PT and BR still diverge

The AO90 was built on a pronunciation principle: if a consonant is no longer pronounced, it should not be written. But "no longer pronounced" turned out to depend on which country you asked.

In many words, both varieties agreed the consonant was silent, so both dropped it. The merged spellings are now universal:

But in a smaller set of words, the consonant is genuinely still pronounced in Portugal (even if weakly) and genuinely not pronounced in Brazil. In these cases, AO90 preserves the consonant only in the variety that pronounces it, producing divergent modern spellings:

2. Tonic accents — accent marks that moved or merged

A second domain the AO90 changed was accent placement. Several words that had differentiating accents lost them, while others kept them. Here the reform worked the same way in both countries, but the state of affairs after reform still leaves divergences because some words only exist with their accent in one variety.

Accents removed in both varieties

Context now disambiguates all of these. If you see "o comboio para na estação", context tells you this is the verb (the train stops); if you see "o comboio para a estação", context tells you this is the preposition (the train to/toward the station).

Accents preserved because homography would be worse

A smaller group of words kept their differentiating accents because removing them would cause real ambiguity that context alone wouldn't resolve. These are shared across both varieties:

3. Circumflex on closed vowels — where the varieties still differ

The most visually striking remaining spelling difference is the circumflex accent on closed vowels before nasal consonants. PT-PT drops it; BR keeps it. Both are AO90-compliant — the reform allowed each country to retain its native pronunciation pattern.

The pattern: when the vowel is followed by a nasal consonant (n, m, nh) and is pronounced as a closed vowel in PT-PT but a closer, higher-pressure vowel in BR, the varieties split. The acute accent (´) in PT-PT indicates an open pronunciation; the circumflex (^) in BR indicates a closed one. This reflects a genuine pronunciation difference — not just a spelling preference.

4. Hyphens — where the reform touched only lightly

The AO90 reformed some hyphen usage but left much of the existing system intact. The one high-profile change learners encounter is the hyphenation of compound nouns.

In practice, some PT-PT publishers and writers have continued to hyphenate fim-de-semana and dia-a-dia even in AO90 texts, treating them as single lexical items. This is technically non-compliant but widespread — you will see both. Brazilian usage is firmly unhyphenated.

Hyphenation was preserved in compound nouns with a clear internal structure — names of chemicals (ácido-clorídrico), compound professions (médico-cirurgião), reduplicative forms (ziguezague, tique-taque) — and in verb + clitic constructions (diz-me, levá-los) across both varieties.

5. Pre-reform spellings you will still see

Because PT-PT usage is divided on the reform, learners of PT-PT must be able to read pre-AO90 spellings fluently, even if they write in AO90 themselves. The words you will most commonly encounter in older or unreconstructed texts:

Crucially, note one spelling that did NOT change in PT-PT: contacto (contact). BR dropped the /c/ to write contato. PT-PT kept the /c/ because Portuguese speakers still pronounce it. So the modern divergence is contacto (PT-PT) vs. contato (BR) — and this is not a pre-reform vs. post-reform split but a genuine modern orthographic difference.

6. Umlauts and tremas — a Brazilian relic

Brazilian Portuguese, before AO90, used the trema (¨) over the u in words like lingüística, agüentar, qüinqüênio to signal that the u is pronounced (not silent as in quente). The AO90 abolished the trema in both varieties for common nouns (it survives only in foreign names: Müller, Hübner). Portugal had already abandoned the trema decades before AO90, so for PT-PT this was a non-change; for BR it was a visible reform.

You will see tremas only in pre-2012 Brazilian texts and in foreign proper nouns. PT-PT has never used them in modern orthography.

7. The letters k, w, y — welcomed back

AO90 formally readmitted k, w, y to the Portuguese alphabet as full letters (they had been treated as foreign imports). In practice this affects only loanwords and names (kilo → kg, watt, byte, yoga). No everyday vocabulary changed — this was a status change, not a spelling change.

8. A side-by-side paragraph

To see the accumulated effect of the remaining differences, here is a single paragraph in both post-AO90 varieties. Only the words that still differ are shown in bold.

PT-PT: O António é arquiteto e trabalha num setor muito específico da reabilitação. Ele acha que o facto de ter mudado de escritório foi ótimo — o novo espaço tem uma receção mais acolhedora e um aspeto moderno. Passa grande parte do fim de semana a estudar questões económicas e a preparar contactos para novos clientes.

BR: O Antônio é arquiteto e trabalha num setor muito específico da reabilitação. Ele acha que o fato de ter mudado de escritório foi ótimo — o novo espaço tem uma recepção mais acolhedora e um aspecto moderno. Passa grande parte do fim de semana a estudar questões econômicas e a preparar contatos para novos clientes.

The two paragraphs are 98% identical. The differences: António/Antônio, facto/fato, receção/recepção, aspeto/aspecto, económicas/econômicas, contactos/contatos. Six word-forms out of roughly eighty words — but every one of them is a reliable text-origin signal.

Common mistakes

Mistake 1: Treating pre-reform spellings as wrong.

Mistake 2: Mixing up facto and fato.

Mistake 3: Using the circumflex on António, ténis, económico in PT-PT writing.

Mistake 4: Hyphenating fim de semana outside AO90.

Mistake 5: Writing contato in PT-PT.

Key takeaways

• The Acordo Ortográfico de 1990 merged roughly 98% of PT-PT/BR spelling. It took effect in Portugal in 2008 (full compliance by 2015) and in Brazil in 2009 (compliance by 2012).
• Silent consonants were dropped where both varieties agreed they were silent (acção → ação) but preserved where one variety still pronounces them: facto/fato, receção/recepção, contacto/contato.
• Circumflex on closed vowels before nasals is the most visible remaining difference: PT-PT uses acute (António, ténis, económico); BR uses circumflex (Antônio, tênis, econômico).
• Pre-reform spellings (acção, óptimo, adopção, arquitecto, directo, sector, eléctrico, excepção, sumptuoso) still appear in PT-PT sources — learners must recognise them.
• Tremas (¨) are gone from common nouns in both varieties; they survive only in foreign names.
• Hyphens in compounds like fim de semana were simplified by AO90; PT-PT usage is inconsistent, BR is strict.
• Differentiating accents on short homographs were mostly merged (pára → para, pêra → pera); the critical survivors are pôr/por and pôde/pode.
• The letters k, w, y are formally part of the Portuguese alphabet post-AO90.
• Portugal's adoption of AO90 remains politically contested — some serious publications continue to reject the reform. Learners should write in AO90 and read both.