Ask at the forum if you have an Ancient or Modern Greek query!
Genuinely: P. ἀληθινῶς, ἀκιβδήλως, P. and V. γνησίως.
As opposed to nominally: P. and V. ἔργῳ, V. ἔργοις.
Indeed, truly: P. and V. ἀληθῶς, ὄντως, P. τῷ ὄντι, V. ἐτητύμως; see truly.
Is it so? Ar. and V. ἀληθές;