Notes: Trubetzkoy 1930,87 compares WC *q́I:a 'to be' with another PEC stem (*ʔikV q.v.), which is impossible for phonetic reasons. The comparison with *=Hŏq̇_Ē seems quite plausible semantically and phonetically.
A similar root exists in Kartvelian (Georg. q̇a-w- 'to be, to have'); its comparison with WC see in Charaya 1912, 37, Lomtatidze 1956, 225, 228; the nature of its connection with the NC root is yet to be cleared up.