PS

*kwn/*kyn - to be steadfast, sure, reliable (Kogan 2015:560)

PWS
*kwn - to be (Kogan 2015: 86)
Akk. kânu ‘to be firm in place, to remain stationary, to be reliable, correct’ provides a suitable source of semantic development

Akkadian
kânu - to be firm in place, to remain stationary, to be reliable, correct (CAD K 159, AHw. 438)
Akkadian
kēna - yes (CAD K 311; AHw. 479)
Hebrew
kēn - correct, right, certain (HALOT 482)