How does the Svan vowel system differ from the vowel systems of other Kartvelian languages?

The Svan language, a member of the Kartvelian languages family, possesses a more complex vowel system than its relatives, such as Georgian, Mingrelian, and Laz.12

While all Kartvelian languages share the five cardinal vowels (a, e, i, o, u), Svan dialects are distinguished by several additional features:

• Additional Vowels: Svan includes front (palatalized) vowels (ä, ö, ü) and a high central vowel (ə).3
• Vowel Length: Svan dialects utilize distinctive vowel length, meaning all vowels have lengthened counterparts. In some Svan dialects, this results in a total of 18 distinctive vowels.3

In contrast, vowel length is not a distinctive feature in the other Kartvelian languages. These phonological differences, alongside the preservation of various archaic structural features, reflect the early separation of Svan from the rest of the Kartvelian language family.324