Differences Between Spanish and Portuguese - Phonology

Phonology

Although the vocabularies of Spanish and Portuguese are very similar (at times identical), both languages differ phonologically from each other. Phonetically Portuguese is closer to Catalan or to French while the phonetics of Spanish are much closer to Sardinian and the Southern Italian dialects. Portuguese has a larger phonemic inventory than Spanish. That could explain why it is generally not very intelligible to Spanish speakers despite the strong lexical similarity between the two languages; Portuguese speakers have a greater intelligibility of Spanish than do the reverse.

One of the main differences between the Spanish and Portuguese pronunciation are the vowel sounds. Spanish has a basic vowel phonological system, with five phonemic vowels (/a/, /e̞/, /i/, /o̞/, /u/). Phonetic nasalization occurs in Spanish for vowels occurring between nasal consonants or when preceding a syllable-final nasal consonant (/n/ and /m/), but it is not distinctive as in Portuguese. On the other hand, Portuguese has eight to nine oral vowels (/a/, /ɐ/, /e/, /ɛ/, /ɨ/, /i/, /o/, /ɔ/, /u/) (/ɐ/ is closer to in Portugal, while the near-close near-back unrounded vowel /ɨ/—also rendered as or —is only found in European Portuguese) plus five phonemic nasal vowels (/ɐ̃/, /ẽ/, /ĩ/, /õ/, /ũ/) when preceding an omitted syllable-final nasal (⟨n⟩ and ⟨m⟩) or when is marked with a tilde (~): ⟨ã⟩ and ⟨õ⟩. Portuguese, as Catalan, uses vowel height, contrasting stressed and unstressed (reduced) vowels. Moreover, Spanish has two semivowels as allophones, ; while Portuguese has four, two oral, and two nasalized glides, (non-syllabic near-close vowels, as those of most English speech, are allophones of the glides in the Brazilian dialects where near-closeds are used).

The following considerations are based on a comparison of standard versions of Spanish and Portuguese. Apparent divergence of the information below from anyone's personal pronunciation may indicate one's idiolect (or dialect) diverges from the mentioned standards. Information on Portuguese phonology is adapted from Celso Pedro Luft (Novo Manual de Português, 1971), and information on Spanish phonology adapted from Manuel Seco (Gramática Esencial del Español, 1994).

Comparing the phonemic inventory of the two languages, a noticeable divergence stands out. First, Portuguese has more phonemes than Spanish. Also, each language has phonemes that are not shared by the other.