What is "graeco-phrygian"

Graeco-Phrygian 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. says that, in regard to the classification of these languages, their surviving texts—because of their scarcity and/or their nature—can't be quantified.

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

• a certain class of masculine nouns in the nominative singular ending in -s;
• a certain class of denominal verbs;
• the pronoun auto-;
• the participial suffix -meno-;
• the stem kako-;
• and the conjunction ai.