Proto-Mayan language

[2] The Proto-Mayan liquid [r] is reflected as [j] in the western languages (Chujean–Qʼanjobʼalan and Cholan), Huastecan and Yukatek but as [tʃʰ] in Mamean and [r] in Kʼichean and Poqom.

[5] Only Kʼichean–Mamean and some Qʼanjobʼalan languages have retained Proto-Mayan uvular stops [q] and [qʼ] whereas all other branches have changed these into [k] and [kʼ] respectively.

[6] In polysyllabic words Kaqchikel and Tzʼutujil have changed a final Proto-Mayan *[w] and *[ɓ] into [j] and *[ʔ] respectively.

All Cholan languages have changed long proto-Mayan vowels [eː] and [oː] into [i] and [u] respectively.

Vowel length distinction has been lost in Qʼanjobʼalan-Chujean (except for Mochoʼ and Akateko), Kaqchikel and Cholan.