A nasal "i" can be an allophone of "ɨ".
All twelve vowels can be nasalised - before <m> or <n>.
in the roman transcriptions given, the syllable-coda n represents the nasalization of the preceding vowel,
while the syllable-initial n represents the consonant /n/.
A nasal, before a homorganic consonant, is realized as nasalization of the previous vowel.
