For instance, I translated the sentence "The old man saw the goddess just before nightfall" as "ὁ γερων την θεαν ὑπο νυκτα εἰδεν". However, the answer key goes for "ὁ γερων εἰδε την θεαν ὑπο νυκτα". Is the translator simply putting emphasis on the "see" rather than some other form of interaction with the goddess (which seems unlikely to me), or is there something I'm missing?
Ancient Greek word order patterns
(not rules) are dependent on genre, dialect and author.
The answer-key word order looks suspiciously like English. A clause initial subject followed immediately by the main verb followed by the direct object is grammar textbook English syntax and by no means
normal in ancient greek narrative. A common word order in Johannine narrative introducing speech (a narrative sub-genre) John 11:21a εἶπεν οὖν ἡ Μάρθα πρὸς τὸν Ἰησοῦν· John 4:21 λέγει αὐτῇ ὁ Ἰησοῦς· πίστευέ μοι, γύναι, ὅτι ἔρχεται ὥρα ... Note that the subject follows the main verb and the person spoken to may precede the subject.
Sophocles likes to pile up modifiers in front of substantives and nouns. Here is an example from Aeschylus Agamemnon. This is also a species of speech introduction (oratio obliqua, metaphorical).
μαρτυρεῖ δέ μοι κάσις
πηλοῦ ξύνουρος διψία κόνις τάδε ...
The subject here is κόνις (dust) which arrives rather late in the clause. Note the clause initial main verb μαρτυρεῖ (bear witness) followed by the the person spoken to μοι. The string of modifiers διψία (thirsty) and κάσις πηλοῦ ξύνουρος “twin-sister of mud” (LSJ); all of these modifiers are piled up in front of the noun κόνις they modify. Sophocles does this a lot.
Clause initial main verbs are not anything like a rule. But some analysts of Koine consider any substantive fronted (left of the main verb) to be highlighted (increased salience). This is a very complex question. Certain constituents are regularly found before the main verb, for example genitive absolutes which serve as contextualizers in narrative are often clause initial.
Matt. 2:19 Τελευτήσαντος δὲ τοῦ Ἡρῴδου ἰδοὺ ἄγγελος κυρίου φαίνεται κατ᾿ ὄναρ τῷ Ἰωσὴφ ἐν Αἰγύπτῳ
On Attic Tragedy & Herodotus consult:
Helma Dik Word Order in Greek Tragic Dialogue
Helma Dik, Word Order in Ancient Greek: A Pragmatic Account of Word Order Variation in Herodotus.
Just some random observations on constituent order.
C. Stirling Bartholomew