Vowels

Avatime has nine vowels, /i ɪ e ɛ a ɔ o ʊ u/, though the vowels /ɪ ʊ/ have been overlooked in most descriptions of the language. It is not clear if the difference between /i e o u/ and /ɪ ɛ ɔ ʊ/ is one of advanced and retracted tongue root (laryngeal contraction), as in so many languages of Ghana, or of vowel height: different phonetic parameters support different analyses.^{[note 1]}

Avatime has vowel harmony. A root many not mix vowels of the relaxed /i e o u/ and contracted /ɪ ɛ a ɔ ʊ/ sets, and prefixes change vowels to harmonize with the vowels of the root. For example, the human singular gender prefix is /ɔ ~ o/, and the human plural is /a ~ e/: /o-ze/ "thief", /ɔ-ka/ "father"; /be-ze/ "thieves", /ba-ka/ "fathers"; also /o-bu/ "bee" but /ɔ-bʊ/ "god".^{[note 2]}

Vowels may be long or short. Records from 1910^{[clarification needed]} showed that all vowels could be nasalized, but that is disappearing, and few words with nasal vowels remained by the end of the century.

Consonants

/ɸ/ is found in Ewe borrowings, as is /kʷ/, which can be seen to be distinct from /kw/ (which cannot be followed by another consonant) in the loanword /àkʷlɛ̄/ "boat".

The language has been claimed to have doubly articulated fricatives /x͡ɸ ɣ͡β/. However, as with similar claims for Swedish [ɧ], the labial articulation is not fricated, and these are actually labialized velars, /xʷ ɣʷ/. All velar fricatives are quite weak, and are closer to [h ɦ hʷ ɦʷ].

The affricates vary between [t͡s], [d͡z] and [t͡ʃ], [d͡ʒ], which may be a generational difference.

Phonotactics

Syllables are V, CV, CGV, and N: Avatime allows consonant-approximant clusters, where the approximant may be /l/, /w/, /j/. There is also a syllabic nasal, which takes its own tone: /kpāŋ̄/ "many".

Any consonant but /n/, /l/ may form a cluster with /l/: /ɔ̀kplɔ̄nɔ̀/ "table", /ɔ̀ɡblāɡɛ̄/ "snake", /káɣʷlɪ̀tsã̀/ "chameleon", /sɪ̄ŋʷlɛ̀sɛ̃̀/ "mucous". After a coronal consonant, the /l/ is pronounced [r].

When two vowels come together, they are either separated by a glottal stop [ʔ], fuse into a single vowel, or the first vowel reduces to a semivowel. In the latter case, the four front vowels reduce to [j] and three of the back vowels reduce to [w], but /u/ is fronted to [ɥ].

However, there are /Cw/ and /Cj/ sequences which are not derived from vowel sequences. These are /fw/, /mw/, /fj/, /vj/, /βj/, /tj/, /dj/, /sj/, /zj/, /lj/, /ŋʷj/.