Herbert Weir Smyth, A Greek Grammar for Colleges

After primary tenses in the apodosis, we have εἰ with the indicative or ἐά_ν (πως) with the subjunctive; after secondary tenses, εἰ with the optative or, occasionally, ἐά_ν (πως) with the subjunctive. Homer has sometimes the optative after primary tenses. The reference is to the future as in final clauses.

The protasis here depends, not on the apodosis proper, but on the idea of purpose or desire suggested by the thought. The accomplishment of the purpose may be desired or not desired, and by the subject either of the apodosis or of the protasis.

νῦν αὖτ᾽ ἐγχείῃ πειρήσομαι, αἴ κε τύχωμι but now I will make trial with my spear on the chance (in the hope) that I may hit thee E279, ἄκουσον καὶ ἐμοῦ, ἐά_ν σοι ἔτι ταὐτὰ δοκῇ listen to me too on the chance (in the hope) that you may still have the same opinion P. R. 358b, ““πορευόμενοι ἐς τὴν Ἀσία_ν ὡς βασιλέα_, εἴ πως πείσειαν αὐτόν” going into Asia to the king in the hope that somehow they might persuade him” T. 2.67, πρὸς τὴν πόλιν, εἰ ἐπιβοηθοῖεν, ἐχώρουν they advanced toward the city on the chance that they (the citizens) should make a sally 6. 100.

N.—This use is to be distinguished from that of εἰ ἄρα if perchance, εἰ μὴ ἄρα unless perchance (often ironical).

a. This construction should be distinguished from cases like ““ἐπιβουλεύουσιν . . . ἐξελθεῖν . . ., ἢν δύνωνται βιάσασθαι” they planned to get out, if they might make their way by force” T. 3.20, where we have implied indirect discourse (ἐξέλθωμεν, ἢν δυνώμεθα βιάσασθαι).

b. Homer uses this construction as an object clause in dependence on οἶδα, εἶδον, or on a verb of saying. Thus τίς δ᾽ οἶδ᾽, εἴ κέν οἱ σὺν δαίμονι θυ_μὸν ὀρί_νω παρειπών; who knows if, perchance, with God's help I may rouse his spirit by persuasion? O 403 (i.e. the chances of rousing his spirit, if haply I may), ἐνίσπες, εἴ πως . . . ὑπεκπροφύγοιμι Χάρυβδιν tell me if haply I shall (might) escape Charybdis μ 112. Here the apodosis is entirely suppressed. Observe that this construction is not an indirect question.

LESS USUAL COMBINATIONS OF COMPLETE PROTASIS AND APODOSIS