Suyá language

Kĩsêdjê preserved the consonants of Proto-Tapajós almost intact, with the exception of the sound change *t̪ʰ > s.[5]^: 560

The following table lists some of the possible onsets of Kĩsêdjê;[6]^: 126 in addition, most of these can further combine with /w/ or /ɲ/ (in words whose Proto-Northern Jê etyma contain one of *wa, *wə̂, or *jê, which are analyzed as complex nuclei). Underlying nasals acquire an oral phase preceding an oral nucleus.[6]^: 127–8

The vowel inventory of Kĩsêdjê is shown below (the orthographic representation is given in italics; the characters in slashes stand for the IPA values of each vowel).[6]^: 125 Nonato (2014) reports that there is no allophonic variation.[6]^: 127 By convention, the tilde, which is part of the graphemes that denote nasal vowels, is left out in the orthography following <m>, <n>, and <nh> (but not <ng>), as in <mo> [mɔ̃] ‘to go (plural)’. In addition, the vowels /ɘ̃/ and /ã/ are not differentiated in the orthography (both are written as <ã>).[6]^: 130–1

Kĩsêdjê has a phenomenon whereby an echo vowel is obligatorily inserted in utterance-final words whose underlying form ends in a consonant;[6]^: 128–30[7] that way, all utterances end in vowels on surface in Kĩsêdjê. Vowel epenthesis often causes the underlying coda to lenite. The resulting alternations are represented orthographically, as in thep [ˈt̠ʰɛp̚] / thewe [ˈt̠ʰɛwɛ] ‘fish’, wit [ˈwit̚] / wiri [ˈwiɾi] ‘only’, ngrôt [ˈŋgɹot̚] / ngrôrô [ˈŋgɹoɾo] ‘the Pleiades’, khẽn [ˈkʰɛ̃n̚] / khẽne [ˈkʰɛ̃nɛ̃] ‘stone’, hwysysôm [hʷɨsɨˈsom̚] / hwysysômy [hʷɨsɨˈsomɨ] ‘mosquito’.[7] In words that end in an underlying rhotic coda, echo vowels are inserted regardless of whether the word is in the utterance-final position, as in ngõrõ [ˈŋɔ̃ɽɔ̃] ‘to sleep’ (forms such as *[ˈŋɔ̃ɽ] are unattested).[6]^: 128–30

As in all other Northern Jê languages, verbs inflect for finiteness and thus have a basic opposition between a finite form (also form B[4] and main form[6]) and a nonfinite form (also form A[4] and embedded form[6]). Finite forms are used in matrix clauses only, whereas nonfinite forms are used in all types of subordinate clauses[6]^: 140 as well as in some matrix clauses.[8][9] Nonfinite forms are most often formed via suffixation and/or prefix substitution. Some verbs (including all descriptives with the exception of katho ‘to leave’, whose nonfinite form is kathoro) lack an overt finiteness distinction.

The available nonfinite suffixes are /-ɽ/ (the most common option, found in many transitive and intransitive verbs, with its allomorph /-j/ after the vowel /a/), /-n/ (found in some transitive verbs), as well as /-k/, /-m/, and /-t/ (found in a handful of intransitive verbs which take a nominative subject when finite), as shown in the table below.[6][4]

In Proto-Northern Jê, several verbs derived their finite forms by means of leniting the stem-final consonant (*-t, *-c, *-k → *-r, *-j, *-r).[5]^: 544 In Kĩsêdjê, at least three verbs retain this pattern,[6][4] though the relation between the finite and nonfinite forms has been obfuscated by a series of regular sound changes, including *-ôj > -wâj (-âj after a labial), *-c > -t.

In Proto-Northern Jê, a small set of verbs formed their nonfinite forms by employing one of the aforementioned processes and a morphophonological process whereby the onset of the stressed syllable became palatal, and the nucleus of the stressed syllable was raised (if possible); this has been attributed to the influence of an underlying palatalizing nonfinite prefix. In Kĩsêdjê, some of these verbs still follow the archaic pattern, though the relation between the finite and nonfinite forms has been obfuscated by a series of regular sound changes.[5]

In addition to the aforementioned processes, the finiteness inflection may involve prefix substitution or loss. For example, the valency-reducing prefixes are a(j)- (anticausative) and a- (antipassive) in finite verb forms, but wi- and tá-/tu-, respectively, in the nonfinite forms.[5]^{: 541, 544} In addition, some verbs which denote physiological activities or movement have a prefix (i- and a-, respectively) in their finite forms but not in the nonfinite form. Some examples are given below.[10]