The Proto-Kartvelian language, or Common Kartvelian (Georgian: წინარექართველური ენა, romanized: ts'inarekartveluri ena, Georgian: პროტოქართველური ენა, romanized: p'rot'okartveluri ena), is the linguistic reconstruction of the common ancestor of the Kartvelian languages, which was spoken by the ancestors of the modern Kartvelian peoples.
[1] Several linguists, namely Gerhard Deeters and Georgy Klimov have also reconstructed a lower-level proto-language called Proto-Karto-Zan or Proto-Georgian-Zan, which is the ancestor of Karto-Zan languages (includes Georgian and Zan).
[3] This is reinforced by cognates with Indo-European, such as the Proto-Kartvelian *mḳerd- ('breast'), and its possible relation to the Proto-Indo-European *ḱerd- ('heart').
[1][better source needed] The modern descendants of Proto-Kartvelian are Georgian, Svan, Mingrelian and Laz.
The ablaut patterns of Proto-Kartvelian were better preserved in Georgian and (particularly) Svan than in either Mingrelian or Laz, in which new forms have been set up so that there is a single, stable vowel in each word element.