Guarani Phonology

Guarani syllables consist of a consonant plus a vowel or a vowel alone; syllables ending in a consonant or two or more consonants together do not occur. This is represented as (C)V(V).

• Vowels: /a/, /e/, /i/, /o/, /u/ correspond more or less to the Spanish and IPA equivalents, although sometimes the allophones [ɛ], [ɔ] are used more frequently; the grapheme ⟨y⟩ represents the vowel /ɨ/ (as in Latgalian).

Oral and nasal vowels

	Front	Central	Back
Close	/i/, /ĩ/	/ɨ/, /ɨ̃/	/u/, /ũ/
Mid	/e/, /ẽ/		/o/, /õ/
Open		/a/, /ã/

Consonants:^[19]

IPA value is shown. The orthography is shown in angle brackets below, if different.

		Labial	Alveolar	Alveolo-palatal	Velar	Lab. velar	Glottal
Stop	Voiceless	p	t		k	kʷ ⟨ku⟩	ʔ ⟨'⟩
	Voiced	ᵐb~m ⟨mb~m⟩	ⁿd~n ⟨nd~n⟩	ᵈj~ɲ ⟨j~ñ⟩	ᵑɡ~ŋ ⟨ng⟩	ᵑɡʷ~ŋʷ ⟨ngu⟩
Fricative			s	ɕ ⟨ch⟩	x~h ⟨h⟩
Approximant		ʋ ⟨v⟩			ɰ ~ ɰ̃ ⟨g⟩ ~ ⟨g̃⟩	w ~ w̃ ⟨gu⟩ ~ ⟨g̃u⟩
Flap			ɾ ⟨r⟩

The voiced consonants have oral allophones (left) before oral vowels, and nasal allophones (right) before nasal vowels. The oral allophones of the voiced stops are prenasalized.

There is also a sequence /ⁿt/ (written ⟨nt⟩). A trill /r/ (written ⟨rr⟩), and the consonants /l/, /f/, and /j/ (written ⟨ll⟩) are not native to Guarani, but come from Spanish.

Oral [ᵈj] is often pronounced [dʒ], [ɟ], [ʒ], [j], depending on the dialect, but the nasal allophone is always [ɲ].

The dorsal fricative is in free variation between [x] and [h].

⟨g⟩, ⟨gu⟩ are approximants, not fricatives, but are sometimes transcribed [ɣ], [ɣʷ], as is conventional for Spanish. ⟨gu⟩ is also transcribed [ɰʷ], which is essentially identical to [w].

All syllables are open, viz. CV or V, ending in a vowel.

Glottal stop

The glottal stop is only written between vowels, but occurs phonetically before vowel-initial words. Because of this, Ayala (2000:19) shows that some words have several glottal stops near each other, which consequently undergo a number of different dissimilationtechniques. For example, "I drink water" 'a'u'y is pronounced hau'y. This suggests that irregularity in verb forms derives from regular sound change processes in the history of Guarani. There also seems to be some degree of variation between how much the glottal stop is dropped (for example aru'uka > aruuka > aruka for "I bring"). It is possible that word-internal glottal stops may have been retained from fossilized compounds where the second component was a vowel-initial (and therefore glottal stop–initial) root.^[20]:19

Nasal harmony

Guarani displays an unusual degree of nasal harmony. A nasal syllable consists of a nasal vowel, and if the consonant is voiced, it takes its nasal allophone. If a stressed syllable is nasal, the nasality spreads in both directions until it bumps up against a stressed syllable that is oral. This includes affixes, postpositions, and compounding. Voiceless consonants do not have nasal allophones, but they do not interrupt the spread of nasality.

For example,

/ⁿdo+ɾoi+ⁿduˈpã+i/ → [nõɾ̃õĩnũˈpãĩ]

/ro+ᵐbo+poˈrã/ → [ɾ̃õmõpõˈɾ̃ã]

However, a second stressed syllable, with an oral vowel, will not become nasalized:

/iᵈjaˈkãɾaˈku/ → [ʔĩɲãˈkãɾ̃ãˈku]

/aˈkãɾaˈwe/ → [ʔãˈkãɾ̃ãˈwe]^[21]

That is, for a word with a single stressed vowel, all voiced segments will be either oral or nasal, while voiceless consonants are unaffected, as in oral /ᵐbotɨ/ vs nasal /mõtɨ̃/.

https://en.m.wikipedia.org/wiki/Guarani_language