Where does “-ու-” come from?

-ու- (Old Armenian) comes from Proto-Indo-European -kyā-, from Proto-Indo-European -k-.

Ancestry of “-ու-”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	-kyā-	—
2	Proto-Indo-European	-k-	—

-ու- — Etymology, Origin & Word History | Etymology Explorer