G4258–προαμαρτάνω–proamartanō

And lest, when I come again, my God will humble me among you, and that I shall bewail many which have sinned already, and have not repented of the uncleanness and fornication and lasciviousness which they have committed.

προημαρτηκότων proēmartēkotōn “having sinned before”

I told you before, and foretell you, as if I were present, the second time; and being absent now I write to them which heretofore have sinned, and to all other, that, if I come again, I will not spare:

προημαρτηκόσιν proēmartēkosin “having sinned before”