More vivid future conditions have in the protasis ἐά_ν (ἤν, ἄ_ν) with the subjunctive; in the apodosis, the future indicative or any other form referring to future time.
ἐὰ_ν ταῦτα ποιῇς (ποιήσῃς), καλῶς ποιήσεις
This form of condition corresponds to the use of
Modern English substitutes the present for the more exact future in ordinary future conditions of this class; and often uses shall in the protasis with an emotional force. The English present subjunctive, although somewhat rarely used in the modern language, corresponds more nearly to the Greek subjunctive (“if she be there, he shall not need”: Beaumont and Fletcher).—Since if you do this may be expressed in Greek by ἐὰ_ν ταῦτα ποιῇς or εἰ ταῦτα ποιήσεις ( cross2328), and by εἰ ταῦτα ποιεῖς ( cross2298), the difference in meaning is made clear only by the apodosis. The form ἐὰ_ν ταῦτα ποιῇς in vivid future conditions must be distinguished from the same form in present general conditions (
The present subjunctive views an act as continuing (not completed); the aorist subjunctive as simply occurring (completed). Neither tense has any time of itself. The aorist subjunctive may mark the action of the protasis as completed before the action of the principal clause (cp. the Lat. future perfect). Ingressive aorists ( cross1924) retain their force in the subjunctive.2326
The apodosis of the more vivid future condition is the future indicative or any other form of the simple sentence that refers to future time.
a. Future Indicative:
ἐὰ_ν ζητῇς καλῶς, εὑρήσεις
ἐὰ_ν δ' ἔχωμεν χρήμαθ', ἕξομεν φίλους
χάριν γε εἴσομαι, ἐὰ_ν ἀκούητε
ἢν γὰρ τοῦτο λάβωμεν, οὐ δυνήσονται μένειν
b. Primary Tenses of the indicative other than the future. Present ( cross1879):
ἢν θάνῃς σύ, παῖς ὅδ' ἐκφεύγει μόρον
c. Subjunctive of exhortation, prohibition, or deliberation, and with μή (μὴ οὐ) of doubtful assertion ( cross1801). Thus, μηδ' ἄ_ν τι ὠνῶμαι, ἔφη, ἢν πωλῇ νεώτερος τριά_κοντα ἐτῶν, ἔρωμαι, ὁπόσου πωλεῖ; even if I am buying something, said he, am I not to ask ‘what do you sell it for?’
d. Optative of wish, or potential optative with ἄν (‘something may happen’ instead of ‘something will happen’). Thus, ἤν σε τοῦ λοιποῦ ποτ' ἀφέλωμαι χρόνου,
. . .
e. Imperative, or infinitive for the imperative ( cross2013):
ἢν πόλεμον αἱρῆσθε, μηκέτι ἥκετε δεῦρο ἄνευ ὅπλων
σὺ δ', ἄ_ν τι ἔχῃς βέλτι_όν ποθεν λαβεῖν, πειρᾶσθαι καὶ ἐμοὶ μεταδιδόναι
Homeric Constructions.—a. εἰ alone without κέ or ἄν with the subjunctive with no appreciable difference from εἴ κε (ἄν): εἴ περ γάρ σε κατακτάνῃ, οὔ σ' . . . κλαύσομαι
b. Subjunctive with κέ in both protasis and apodosis (the anticipatory subjunctive, cross1810): εἰ δέ κε μὴ δώῃσιν, ἐγὼ δέ κεν αὐτὸς ἕλωμαι
c. εἴ (αἴ) κε with the future in protasis (rare): σοὶ . . . ὄνειδος ἔσσεται, εἴ κ' Ἀχιλῆος . . . ἑταῖρον . . . κύνες ἑλκήσουσιν
Emotional Future Conditions.—When the protasis expresses strong feeling, the future indicative with εἰ is commonly used instead of ἐά_ν with the subjunctive, and may often be rendered by hall. The protasis commonly suggests something undesired, or feared, or intended independently of the speaker's will; the apodosis commonly conveys a threat, a warning, or an earnest appeal to the feelings. The apodosis is generally expressed by the future indicative, but other forms of 2326 are possible.
εἰ ταῦτα λέξεις, ἐχθαρεῖ μὲν ἐξ ἐμοῦ
ἀποκτενεῖς γάρ, εἴ με γῆς ἔξω βαλεῖς
εἰ ὧδε στρατευσόμεθα, οὐ δυνησόμεθα μάχεσθαι
εἰ φυγὰς ἀδίκως καταστήσομαι
a. When εἰ with the future indicative is directly contrasted with ἐά_ν with the subjunctive, the former usually presents the unfavourable, the latter the favourable, alternative. Thus,
ἢν μὲν γὰρ ἐθέλωμεν ἀποθνῄσκειν ὑπὲρ τῶν δικαίων, εὐδοκιμήσομεν . . ., εἰ δὲ φοβησόμεθα τοὺς κινδύ_νους, εἰς πολλὰ_ς ταραχὰ_ς καταστήσομεν ἡμᾶς αὐτούς
out any essential difference (
b. εἰ with the future indicative may have a modal force like that of δεῖ or μέλλω (
Herbert Weir Smyth [n.d.], A Greek Grammar for Colleges; Machine readable text [info] [word count] [Smyth].