A.T. Robertson Commentary 2 Corinthians 10:11

"Let such a one reckon this, that, what we are in word by letters when we are absent, such [are we] also in deed when we are present." — 2 Corinthians 10:11 (ASV)

What we are (οιο εσμεν). Rather, "what sort" (οιο), not ο (what) nor ο (who). Literary plural. Hοιος is qualitative just as τοιουτο (such). Paul's quality in his letters when absent (αποντες) and in his deeds when present (παροντες) is precisely the same.