Comments: PTsKh *quI (source of pharyngealization unclear); PGB *qʷe (cf. also Tlad. qö). The root *qʷe is a result of reanalysing the final *-bV as a plural suffix (cf. plural forms like Gunz. qebur; note that in Gunz. the oblique stem is also qebo-).
The vocalism is hard to reconstruct (probably some Ablaut type is reflected).