Herbert Weir Smyth, A Greek Grammar for Colleges

REPETITION AND OMISSION OF PREPOSITIONS, ETC.

b. A preposition is used with the first noun and omitted with the second when the two nouns (whether similar or dissimilar in meaning) unite to form a complex: περὶ τοῦ δικαίου καὶ ἀρετῆς ‘concerning the justice of our cause and the honesty of our intentions’ T. 3.10.

c. In poetry a preposition may be used only with the second of two nouns dependent on it: ““Δελφῶν κἀ_πὸ Δαυλία_ς” from Delphi and Daulia” S. O. T. 734.

[*] 1668. In contrasts or alternatives expressed by ἤ, ἢ . . . ἤ, καὶ . . . καί, etc., the preposition may be repeated or omitted with the second noun: ““καὶ κατὰ γῆν καὶ κατὰ θάλατταν” both by land and by sea” X. A. 1.1.7, ““πρὸς ἐχθρὸν ἢ φίλον” to foe or friend” D. 21.114.

[*] 1669. When prepositions of different meaning are used with the same noun, the noun is repeated; thus neither upon (the earth) nor under the earth is οὔτ᾽ ἐπὶ γῆς οὔθ᾽ ὑπὸ γῆς P. Menex. 246d.

[*] 1670. In explanatory appositional clauses (988) the preposition may be repeated for the sake of clearness or emphasis; as ““ἐκ τούτων οἱ ὀνομαστοὶ γίγνονται, ἐκ τῶν ἐπιτηδευσάντων ἕκαστα” the men of mark come from those who have practised each art” P. Lach. 183c, and commonly after demonstratives. The preposition is not repeated when such an appositional clause is closely connected with what precedes: εἰκὸς μηδὲ νομίσαι περὶ ἑνὸς μόνου, δουλεία_ς ἀντ᾽ ἐλευθερία_ς, ἀγωνίζεσθαι nor should you think that you are contending for a single issue alone: to avert slavery instead of maintaining your freedom T. 2.63. A preposition is usually not repeated before descriptive appositional clauses (987): περὶ χρημάτων λαλεῖς, ἀβεβαίου πρά_γματος you are talking about wealth, an unstable thing Com. frag. 3. 38 (No. 128).

[*] 1671. Before a relative in the same case as a noun or pronoun dependent on a preposition, the preposition is usually omitted: ““κατὰ ταύτην τὴν ἡλικία_ν ἦν ἣν ἐγὼ νῦν” he was at that age at which I now am” D. 21.155, φιλεῖται ὑπὸ ὧν ( = τούτων ὧν) ““φιλεῖται” is loved by whom it is loved” P. Euth. 10c. But the preposition is repeated if the relative precedes: ““πρὸς ὅ τις πέφυ_κε, πρὸς τοῦτο ἕνα πρὸς ἓν ἕκαστον ἔργον δεῖ κομίζειν” it is necessary to set each individual to some one work to which he is adapted by nature” P. R. 423d.

[*] 1672. In Plato a preposition is often omitted in replies: ἡττώμενος—ὑπὸ τίνος; φήσει. τοῦ ἀγαθοῦ, φήσομεν overcome—by what? he will say. By the good, we shall say Pr. 355 c.

[*] 1673. The preposition is usually omitted with the main noun or pronoun when it is used in a clause of comparison with ὡς (rarely ὥσπερ) as: ““δεῖ ὡς περὶ μητρὸς καὶ τροφοῦ τῆς χώρα_ς βουλεύεσθαι” they ought to take thought for their country as their mother and nurse” P. R. 414e; so, usually, when the two members are closely united: ““ὡς πρὸς εἰδότ᾽ ἐμὲ σὺ τἀ_ληθῆ λέγε” speak the truth to me as to one who knows” Ar. Lys. 993. The preposition is often omitted in the clause with ὡς (ὥσπερ) as, ἤ than: ““οἳ παρ᾽ οὐδὲν οὕτως ὡς τὸ τοιαῦτα ποιεῖν ἀπολώλα_σιν” who owe their ruin to nothing so much as to such a course of action” D. 19.263, ““περὶ τοῦ μέλλοντος μᾶλλον βουλεύεσθαι ἢ τοῦ παρόντος” to deliberate about the future rather than the present” T. 3.44.

[*] 1674. A preposition with its case may have the function of the subject, or the object, of a sentence; or it may represent the protasis of a condition.

Subject: ““ἔφυγον περὶ ὀκτακοσίους” about eight hundred took to flight” X. H. 6.5.10; (gen. absol.) συνειλεγμένων περὶ ἑπτακοσίους, λαβὼν αὐτοὺς καταβαίνει when about seven hundred had been collected he marched down with them 2. 4. 5. Object: ““διέφθειραν ἐς ὀκτακοσίους” they killed about eight hundred” T. 7.32. Protasis: ““ἐπεὶ διά γ᾽ ὑ_μᾶς αὐτοὺς πάλαι ἂν ἀπωλώλειτε” for had it depended on your selves you would have perished long ago” D. 18.49 (cp. 2344).