If you read Brazilian texts written before about 2012, you will notice spellings that look "wrong" to a modern eye: idéia with an accent, vôo with a circumflex, lingüiça with two dots over the u. They are not typos — they are the old orthography, replaced by the Acordo Ortográfico da Língua Portuguesa of 1990 (usually called the AO90). Brazil began applying it in 2009 and made it mandatory on 1 January 2016. This page tells you exactly what changed, so you can write modern Brazilian Portuguese correctly and read older texts without being confused by accents that no longer exist.
Why the reform exists
Portuguese is an official language across several countries, and before 1990 Brazil and Portugal spelled many words differently. The Acordo's stated goal was to unify the spelling of the Lusophone world — to make a single written standard so that books, laws, and documents could circulate without re-spelling. It did not unify pronunciation or grammar, only the written form, and even then a few differences remain. For a learner of Brazilian Portuguese, the practical upshot is a list of concrete changes, most of which simplify the writing by removing accents.
What changed in Brazilian Portuguese
1. The trema (¨) was abolished
The trema — two dots over a u to show it was pronounced in gue/gui/que/qui groups — is gone in Brazilian Portuguese. The u is still pronounced; we just no longer mark it. (The only place a trema survives is in foreign proper names and their derivatives, like Müller or mülleriano.)
| Old (pre-2009) | New (AO90) | Meaning |
|---|---|---|
| lingüiça | linguiça | sausage |
| freqüente | frequente | frequent |
| tranqüilo | tranquilo | calm |
| cinqüenta | cinquenta | fifty |
| seqüência | sequência | sequence |
✅ A linguiça frequente nos churrascos brasileiros é a toscana.
The sausage commonly found at Brazilian barbecues is the toscana.
2. The acute on paroxytone ei and oi disappeared
Words stressed on the second-to-last syllable (paroxytones) used to carry an acute accent on the diphthongs éi and ói. The AO90 removed that accent. Crucially, this applies only to paroxytones — words stressed on the last syllable (oxytones) like herói, anéis, papéis keep their accent, because the accent rules for oxytones never changed.
| Old | New | Meaning | Why |
|---|---|---|---|
| idéia | ideia | idea | paroxytone — accent dropped |
| heróico | heroico | heroic | paroxytone — accent dropped |
| jibóia | jiboia | boa (snake) | paroxytone — accent dropped |
| assembléia | assembleia | assembly | paroxytone — accent dropped |
| herói | herói | hero | oxytone — accent KEPT |
| papéis | papéis | papers | oxytone — accent KEPT |
✅ Tive uma ideia heroica, mas o herói da história foi outro.
I had a heroic idea, but the hero of the story was someone else.
3. The circumflex on -oo and -eem went away
The circumflex used to mark the closed vowel in double-o endings (vôo) and in the third-person plural of some verbs ending in -eem (lêem, crêem, vêem of the ver family). The AO90 dropped it.
| Old | New | Meaning |
|---|---|---|
| vôo | voo | flight |
| enjôo | enjoo | nausea |
| perdôo | perdoo | I forgive |
| lêem | leem | they read |
| crêem | creem | they believe |
| vêem | veem | they see |
✅ Eles leem o jornal antes do voo da manhã.
They read the newspaper before the morning flight.
Note the careful distinction: vê (he/she sees, singular) keeps its accent — that is an unrelated rule for monosyllabic-stem oxytones. Only the -eem plural lost the circumflex.
4. Disambiguating accents on homographs were removed
Portuguese used to accent certain words purely to tell them apart from look-alikes (the "differential accent"). The AO90 abolished almost all of these. The reasoning: context makes the meaning clear, so the accent was redundant.
| Old | New | Now spelled like its homograph |
|---|---|---|
| pára (verb, stops) | para | = para (preposition, "to/for") |
| pêlo (body hair) | pelo | = pelo ("by the", per + o) |
| pólo (pole / sport) | polo | = polo ("by the", por + o) |
| pêra (pear) | pera | — |
✅ O ônibus para na esquina, então é melhor esperar para atravessar.
The bus stops at the corner, so it's better to wait before crossing.
There are two survivors that still carry differential accents, because dropping them would cause real confusion: pôde (past tense, "he could") vs pode (present, "he can"), and pôr (the verb "to put") vs por (the preposition "by/for"). Learn these two as the exceptions.
✅ Ele não pôde vir ontem, mas hoje ele pode.
He couldn't come yesterday, but today he can.
✅ Vou pôr os livros na estante por você.
I'll put the books on the shelf for you.
5. K, W and Y were readmitted to the alphabet
The Portuguese alphabet officially went from 23 to 26 letters, formally re-adopting k, w, y. In practice these letters appear mostly in foreign words and their derivatives (kg, watt, byte, yoga, show, hacker) and in proper names and their adjectives (Darwin → darwinismo). This did not change how native Portuguese words are spelled, but it tidied up the official inventory. See spelling/alphabet for the full 26-letter list.
6. Hyphenation rules were overhauled
The AO90 substantially rewrote how prefixes and compounds are hyphenated — autoescola joins, anti-inflamatório keeps its hyphen, antirracismo doubles the r. This is the most intricate part of the reform and has its own page: spelling/hyphenation-rules.
Reading older texts
Because the reform is recent, you will constantly meet pre-2009 spellings in books, newspaper archives, song lyrics, and signage that nobody bothered to update. Train your eye to recognize the old forms as equivalent, not wrong-for-their-time:
✅ Numa edição antiga lê-se 'idéia', 'vôo' e 'freqüente' — hoje escrevemos ideia, voo e frequente.
In an old edition you read 'idéia', 'vôo' and 'freqüente' — today we write ideia, voo and frequente.
Common Mistakes
❌ Tive uma idéia ótima ontem.
Incorrect — paroxytone ei lost its acute in the AO90.
✅ Tive uma ideia ótima ontem.
I had a great idea yesterday.
❌ O vôo atrasou três horas.
Incorrect — the circumflex on double-o was abolished.
✅ O voo atrasou três horas.
The flight was delayed by three hours.
❌ Eles lêem muito devagar.
Incorrect — the -eem plural lost its circumflex.
✅ Eles leem muito devagar.
They read very slowly.
❌ Ele não póde terminar a tarefa.
Incorrect — the past tense uses a circumflex (pôde), not an acute.
✅ Ele não pôde terminar a tarefa.
He couldn't finish the task.
❌ A salsicha freqüente no cachorro-quente é a de frango.
Incorrect — the trema no longer exists; write frequente.
✅ A salsicha frequente no cachorro-quente é a de frango.
The sausage commonly used in hot dogs is the chicken one.
Key takeaways
- The trema is gone (frequente, not freqüente).
- The acute dropped on paroxytone ei/oi (ideia, heroico) — but oxytones keep it (herói, papéis).
- The circumflex dropped on double-o and -eem (voo, leem, creem).
- Differential accents removed (para, pelo, polo), with only pôde and pôr surviving.
- k, w, y are now official letters; hyphenation rules changed (see the dedicated page).
- Pre-2009 texts still show the old forms — recognize them as historical equivalents.
Now practice Portuguese
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Start learning Portuguese→Related Topics
- Accent Mark RulesA2 — The rules for when to write an accent in Brazilian Portuguese: all proparoxytones, oxytones ending in -a/-e/-o/-em, paroxytones ending the 'unusual' way, the hiatus rule, and the accents removed by the 2009 reform.
- Hyphenation RulesB2 — Post-AO90 hyphenation hinges on the junction between prefix and base — hyphen for matching vowels or an h-initial base, join (doubling r/s if needed) otherwise, with compounds and bem-/mal- keeping their hyphens.
- Accent Mark ErrorsA2 — The three buckets of accent mistakes — omitting meaning-changing accents, using outdated pre-reform accents, and crase errors — with ❌/✅ pairs.
- BR AlphabetA1 — The 26-letter Brazilian Portuguese alphabet, the name of each letter for spelling aloud, the readmitted K/W/Y, the digraphs (ch, lh, nh, rr, ss, qu, gu, sc), and why 'ç' is not a separate letter.
- BR Spelling: OverviewA1 — A map of the Brazilian Portuguese writing system: the 26-letter alphabet, the five diacritics and what each one does, sound-to-spelling regularity, the 2009 Acordo Ortográfico, and the main trouble spots.