The phonology of Portuguese can vary considerably between dialects, in extreme cases leading to difficulties in intelligibility. This article focuses on the pronunciations that are generally regarded as standard. Since Portuguese is a pluricentric language, and differences between European Portuguese (EP) and Brazilian Portuguese (BP) can be considerable, both varieties are distinguished whenever necessary.
One of the most salient differences between European and Brazilian Portuguese is their prosody. European Portuguese is a stress-timed language, with reduction or even deletion of unstressed vowels and a general tolerance of syllable-final consonants. Brazilian Portuguese, on the other hand, is more or less a syllable-timed language, with no reduction of unstressed vowels and an increasing preference for open syllables, being very tolerant just with rhotics and sibilants on non-final coda. Recent changes in Brazilian Portuguese are steadily eliminating closed syllables: coda nasals are deleted with concomitant nasalization of the preceding vowel, even in learned words; coda /l/ becomes or, except for conservative velarization at the extreme south and rhotacism in remote rural areas in the center of the country; dialectal coda /ʁ/ (/ɾ/ in Europe, as well southern and western dialects) is never trilled outside Rio de Janeiro, thus fricatives (voice depends on following consonant), and is usually deleted entirely when word-final in words with more than one syllable; and /i/ is epenthesized after almost all other coda-final consonants, with only a few clusters tolerated (e.g. /s/+consonant, /ks/). This tends to produce words almost entirely composed of open syllables, e.g. advogado "lawyer"; McDonald's ; rock .
For finer information on regional accents, see Portuguese dialects, and for historical sound changes see History of Portuguese.
Read more about Portuguese Phonology: Consonants, Vowels, Sandhi, Stress, Prosody