Like other Kiranti languages, it displays a fairly complex system of person-marking and stem alternations.
According to records from 2015 BS, the term could have been derived from "kuyama" (IPA- kujämä), words in the Koyee language that mean "dark."
Koyee people who settle down in easter side of Nepal are known as Koyu (कोयू).
Alternate spellings and names are Kohi, Koi B.ʌʔ’, Koyee, Koyi, Koyu.
Koyee is spoken in Sungdel (near Rawakhola headwaters) and Dipsung VDC's, northeastern Khotang District, Koshi Province, Nepal (Ethnologue).