Herbert Weir Smyth, A Greek Grammar for Colleges

After verbs of saying, knowing, perceiving, showing, etc.

After verbs of emotion (rejoicing, grieving, wondering), etc.

Or such dependent statements contain an explanation of the main clause or of a word in that clause, no special verb introducing the conjunction.

τοῦτο ἄξιον ἐπαινεῖν τῶν ἀνδρῶν τῶν τότε ναυμαχησάντων, ὅτι τὸν . . . φόβον διέλυ_σαν τῶν Ἑλλήνων it is right to praise this in the men who engaged in the sea-fight of those days, (namely) that they dispelled the fear felt by the Greeks P. Menex. 241b.