I think Proto-Kartvelian (Proto-South-Caucasian) is reconstructed with a system of ablaut quite similar to PIE. I'm far from an expert on Kartvelian linguistics and I haven't been able to find that much information on Proto-Kartvelian (I'm interested in some good resources if anyone has any), but the ablaut seems quite IE-y with both qualitative and quantitative ablaut and resonants (*i *u *r *l *m *n) often becoming syllabic in the zero grade.Chagen wrote:Are there any cross-linguistic parallels to its ablaut system, for instance?
These two articles might be of interest:
http://www.science.org.ge/2-2/Gamkrelidze.pdf
https://www.academia.edu/4118909/Qualit ... Kartvelian
If you have access to JSTOR, also check out:
Gamkrelidze, Thomas V., A Typology of Common Kartvelian, Language, Vol. 42, No. 1 (Jan. - Mar., 1966), pp. 69-83
Lehmann, W. P., Review of: The System of Sonants and Ablaut in Kartvelian Languages: A Typology of Common Kartvelian Structure by Th. V. Gamkrelidze; G. I. Machavariani, Language, Vol. 44, No. 2, Part 1 (Jun., 1968), pp. 404-407
The reviewed book itself is as far as I'm aware only available in Georgian and Russian (neither of which I can read) but it might be of interest to someone who is able to find it.
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Of some interest also, I think Northwest Caucasian has traces of ablaut aswell with a-grades, ə-grades and zero-grades (remember that these languages are often analyzed as only having two vowel phonemes /a/ and /ə/). This might be most visible in Abkhaz-Abaza.