The subject of the dependent clause is often anticipated and made the object of the verb of the principal clause. This transference, which gives a more prominent place to the subject of the subordinate clause, is called anticipation or prolepsis (πρόληψις taking before).
δέδοικα δ᾽ αὐτὴν μή τι βουλεύσῃ νέον
but I fear lest she may devise something untoward E. Med. 37, ᾔδει αὐτὸν ὅτι μέσον ἔχοι τοῦ Περσικοῦ στρατεύματος
he knew that he held the centre of the Persian army X. A. 1.8.21, ἐπεμέλετο αὐτῶν ὅπως ἀεὶ ἀνδράποδα διατελοῖεν
he took care that they should always continue to be slaves X. C. 8.1.44. Note ὁρᾷς τὸν εὐτράπεζον ὡς ἡδὺς βίος thou seest how sweet is the luxurious life E. fr. 1052. 3.
a. Anticipation is especially common after verbs of saying, seeing, hearing, knowing, fearing, effecting.
b. When a subordinate clause defines a verbal idea consisting of a verb and a substantive, its subject may pass into the principal clause as a genitive depending on the substantive of that clause: ἦλθε δὲ καὶ τοῖς Ἀθηναίοις εὐθὺς ἡ ἀγγελίᾱ τῶ πόλεων ὅτι ἀφεστᾶσι
and there came straightway to the Athenians also the report that the cities had revolted T. 1.61 (= ὅτι αἱ πόλεις ἀφεστᾶσι).
c. The subject of the dependent clause may be put first in its own clause: ἐπιχειρήσωμεν εἰπεῖν, ἀνδρείᾱ τί ποτ᾽ ἐστίν
let us try to say what courage is P. Lach. 190d.
d. The object of the subordinate clause may be anticipated and made the object of the principal clause. Thus, εἰρώτᾱ ὁ Δᾱρεῖος τὴν τέχνην εἰ ἐπίσταιτο
Darius asked if he understood the art Hdt. 3.130.
e. A still freer use is seen in ἐθαύμαζεν αὐτὸν ὁ Λῡ́σανδρος ὡς καλὰ τὰ δένδρα εἴη Lysander marvelled at the beauty of his trees (for τὰ δένδρα αὐτοῦ ὡς κτλ.) X. O. 4. <*>.