ORAL DIPHTHONGS
1) A diphthong is a sequence of a vowel and a semivowel occurring within the same syllable.
The vowel (not the semivowel) forms the nucleus of the syllable (coi-sa).
1
2) The two Portuguese semivowels are transcribed i [
i
] and u [
u
].
3) Most Portuguese oral diphthongs are sequences of an oral vowel + semivowel; these
sequences are often called "falling" diphthongs since the semivowel follows the vowel.
pau / auto // alto / animal (BP)
seu / comeu // feltro (BP)
céu / chapéu // papel (BP)
sou / cantou // soldado (BP)
4) With the exception of [g
u
] / [k
u
] + oral vowel (língua / quarto), the sequences in words like
piano are often pronounced as vowels in hiatus and thus form two syllables (pi-a-no); they
become "rising" diphthongs (= semivowel + vowel) only in fast speech.
6
Since Portuguese
orthography treats these sequences as vowels in hiatus, it marks the vowel of the stressed
syllable preceding two sequentially unstressed vowels (lín-gu-a / gê-ni-o); that is, it counts
these unstressed vowels as two syllables.
9
For the purpose of word division, however,
Portuguese counts these same unstressed sequences as one syllable (lín-gua / gê-nio).
5) BP: [
i
] is often pronounced between a stressed vowel and word-final s / z.
---------------------------------------------------------------------------------------------------------------------
1
See p. 24 for details on syllables and word division.
2
BP: l is often pronounced [
u
] when syllable-final / word-final before a pause (alto = auto).
3
BP: ei is often pronounced [e]; EP: ei is often pronounced [ɐ
i
].
4
EP: Stressed syllable-final ou is often pronounced [o
i
] (and even written oi) (ouro > "oiru").
5
BP: ou is often pronounced [o].
6
Oral triphthongs (which are rare in Portuguese) are sequences of [g
u
] / [k
u
] + oral vowel + [
i
] / [
u
]
(Paraguai / Uruguai / quais // qual / igual [BP; see note 2 above]).
Notes to Spanish Speakers:
7
These diphthongs do not occur in Spanish, although stressed e / o in "falling" diphthongs may
be slightly open (deuda [ɛ] vs. dedo [e] / boina [ɔ] vs. bono [o]) (Quilis and Fernández, Curso 45).
8
Port. fui is a "falling" diphthong [u
i
]; Sp. fui is a "rising" diphthong [
u
i].
9
Since Spanish sequences of semivowel + vowel are considered diphthongs, Spanish does not
mark the vowel of the stressed syllable preceding a semivowel + unstressed vowel
(len-gua / ge-nio); i.e., Spanish counts these sequences as one syllable.