Proto-Mayan phonology

The Proto-Mayan language is reconstructed (Campbell and Kaufman 1985) as having the following sounds:

Five vowels: a, e, i, o and u. Each of these occurring as short and long: aa, ee, ii, oo and uu,

Sound rules
The following set of sound changes from proto-Mayan to the modern languages are used as the basis of the classification of the Mayan languages. Each sound change may be shared by a number of languages; a grey background indicates no change.

Developments
The palatalized plosives and  are not carried down into any of the modern families. Instead they are reflected differently in different branches allowing a reconstruction of these phonemes as palatalized plosives. In the eastern branch (Chujean-Q'anjob'alan and Cholan) they are reflected as and. In Mamean they are reflected as and  and in Yukatek and K'ichean as  and.

The Proto-Mayan liquid is reflected as  in the eastern languages (Chujean- Q'anjob'alan and Cholan), Huastecan and Yukatek but as  in Mamean and  in K'ichean and Poqom.

Proto-Mayan velar nasal is reflected as  in the western branches (K'ichean Mamean), as  in Q'anjob'alan, Cholan and Yukatekan, and only conserved as  in Chuj and Poptí. In Huastecan is reflected as.

The changes of Proto-Mayan glottal fricative are many and it has different reflexes according to position. In some positions it has added length to the preceding vowel in languages that preserve a length distinction. In other languages it has the reflexes, , , or a zero-reflex.

Only K'ichean-Mamean and some Q'anjob'alan languages have retained Proto-Mayan uvular stops and  whereas all other branches have changed these into  and  respectively.

In Mamean a chain shift took place changing into,  into ,  into  and  into. These retroflex affricates and fricatives later diffused into Q'anjob'alan.

In polysyllabic words Kaqchikel and Tz'utujil have changed a final Proto-Mayan and  into  and  respectively.

Huastecan is the only branch to have changed Proto-Mayan into. Wastek also is the only Mayan language to have a phonemic labialized velar phoneme, but this is known to be a postcolonial development. Comparing colonial documents in Wastek to modern Wastek it can be seen that they were originally clusters of and a rounded vowel followed by a glide. For example the word for "vulture" which in modern Wastek is pronounced was written   in colonial Wastek and pronounced.

The Yucatecan languages have all shifted Proto-Mayan into  in wordfinal position.

Several languages particularly Cholan and Yucatecan have changed short into.

All Cholan languages have changed long proto-Mayan vowels and  into  and  respectively.

Vowel length distinction has been lost in Q'anjob'alan-Chujean (except for Mocho' and Akateko), Kaqchikel and Cholan. Some languages have reduced the vowel length distinction into a tense lax distinction that was later lost for most vowels, Kaqchikel however retains a centralized lax schwa-like vowel as a reflex of Proto-Mayan. Two languages, Yukatek and Uspantek and one dialect of Tzotzil have introduced a tone distinction in vowels between high and low tones as reflexes of former vowel length and and.