Tuyuca is a postpositionalagglutinativesubject–object–verb language with mandatory type II evidentiality.[3] Five evidentiality paradigms are used: visual, nonvisual, apparent, second-hand, and assumed, but second-hand evidentiality exists only in the past tense, and apparent evidentiality does not occur in the first-person present tense.[4] The language is estimated to have 50 to 140 noun classes.[5][unreliable source]
Voiceless plosives /p,t,k/ have aspirated variants that tend to occur before high vowels but not near voiceless vowels. There are a few degrees of the amount of aspiration.
Preglottalized variants of /b,d/ occur together at the onset.
Preglottalized forms of [m,w,w̃,j,j̃,ɲ,dʒ] occur in the onset and are in free variation with their plain counterparts.
Prenasal variants of /b,d,ɡ/ occur after nasal vowels and before oral vowels: /kĩĩbai/[kʰĩĩmbaii̥].[7]
There is a high tone (H) and a low tone (L) in Tuyuca. The phonological word has only one high tone, which may occur in any syllable of the word. The low tone has two variants: a mid-tone, which occurs in words with at least three syllables in free variation, and the low tone, which occurs in internal syllables that have [i] that is contiguous to the high tone but not preceded by a low tone.
The accent is the same as high tone.
The tone is contrastive in (C)VV syllables.
/díi/ 'blood'
/dií/ 'mud'
(C)VCV words, except for loanwords, have the tone on the second syllable.
Multisyllabic VVV strings occur, but not all combinations of vowels are attested. /u/ is always last in such strings.
(C)V may be optionally be pronounced with aspiration, with the same quality as the preceding vowel, when the syllable is both unstressed and before syllables with voiceless onsets.[8]