Graeco-Phrygian

Graeco-Phrygian /ˌɡriːkoʊˈfrɪdʒiən/ is a hypothetical branch of the Indo-European language family with two branches in turn: Greek and Phrygian. Greek has also been variously grouped with Armenian (Graeco-Armenian; Graeco-Aryan), Ancient Macedonian (Graeco-Macedonian) and, more recently, Messapian. Multiple or all of these, with the exception of Armenian, are sometimes (tentatively) classified under "Hellenic"; at other times, Hellenic is posited to consist of only Greek. Blažek (2005, p. 6) says that, in regard with the classification of these languages, their surviving texts—because of their scarcity and/or their nature—can't be quantified.

Brixhe (2008) points to these features Greek and Phrygian are known to have in common and in common with no other language:

Bibliography