Brazilian Portuguese keeps every vowel that Lisbon whispers away, which makes it sound like a different language at first. t and d hiss before i — 'dia' is 'jia' — a final l is a w, and Rio specifically turns the r of 'rio' and the r at the end of a word into a breath. The ʃ on final s is one of the few things Rio shares with Lisbon.
Where: Brazil — carioca
The way in: 'Bom dia, Rio' as bõ d͡ʒia hiu.
Try a word
Anything the spelling engine can transcribe, the accent can move. Slow it down to hear the shape.
Syllable-timed where Lisbon is stress-timed: every vowel gets its beat, so the language sounds sung. Rio adds a long, lazy rise on stressed syllables and a rising tail on questions.
What moves, one rule at a time
In the order the mouth applies them. Every before-and-after is playable — click the IPA. The pattern is the rule as the engine runs it, for the curious.
Consonants
t hisses before i
t(?=[iɪ]) → t͡ʃ
When: before i, including the i that a final e has just become
How: Let the t release into the ch of 'church'.
'Tia' is 'chia', 'noite' is 'noichi'. It is the most Brazilian sound there is, and Lisbon does not have it at all.
Word
Reference
Accent
tia
noite
gente
d hisses before i
d(?=[iɪ]) → d͡ʒ
How: 'Dia' is 'jia' — the j of English 'jeep'.
Word
Reference
Accent
dia
verde
cidade
l at the end of a syllable is a w
l(?=[pbtdkɡqʔmnɲŋɴfvθðszʃʒɕʂʐçxχɣʁħʕhβʝlʎɹrɾjwɥʈɖɳɽʋɦ]|$| ) → w
How: Say 'oo' where the l would be.
Which is why 'Brasil' ends in the sound of 'ow'. Lisbon keeps a dark l.
Word
Reference
Accent
Brasil
mal
sol
The strong r is a breath
ʁ → h
How: Just breathe. No tongue, no throat.
Rio's r is the English h. 'Rio' is 'hee-oo'.
Word
Reference
Accent
rio
carro
rua
…and so is r at the end of a word
ɾ$ → h
When: at the end of a word; very often it drops away entirely
Word
Reference
Accent
comer
falar
Vowels
Final unstressed e is a full i
ɨ → i
How: Say a full 'ee'. Every syllable is pronounced.
Brazil never reduced this vowel. It is a clear i — and that i then triggers the next rule.
Word
Reference
Accent
sete
noite
verde
Unstressed a is a full a
ɐ(?![̃]) → a
Lisbon reduces it to a schwa-like ɐ. Brazil says the vowel.