Accentuation rules for Greek accusative forms: no acute on words ending in -α; certain forms are raised or changed by crasis and vowel quality (e.g., Ἐρετριᾶ, Πειραιᾶ); monosyllabic accusatives ending in -ν take different accents (μῦν, μνᾶν, etc.); explanation of Aeolic shortening and forms ending in -ιν analyzed as short in accusative; concept of homochronous isosyllables and their accentuation.
Οὐδεμία εἰς 'α' λήγουσα αἰτιατικὴ ὀξύνεται· —τὸ γὰρ τινά ὀξύνεται εἰς διαφορὰν τοῦ τίνα· —ἔνθεν ἡ νιφάδα ἀποκοπεῖσα ἀνεβιβάσθη «ἀλευόμενοι νίφα λευκήν». τὸ δὲ Ἐρετριᾶ καὶ Πειραιᾶ καὶ Στειριᾶ καὶ χοᾶ κατὰ κρᾶσιν τοῦ 'ε' καὶ 'α' περισπᾶται. Πᾶσα αἰτιατικὴ μονοσύλλαβος εἰς 'ν' λήγουσα περισπᾶται, ἀπέστραπται δὲ τὸν ὀξὺν τόνον μῦν, μνᾶν, σῦν, ὗν, δρῦν, λῖν «ἐπί τε λῖν ἤγαγε δαίμων» (Λ 480), γῆν, ναῦν, γραῦν. θεῦν «τὴν θεῦν Ἄρτεμιν οἷ´ ἔπαθεν» τὴν θεὸν κατὰ κρᾶσιν, νοῦν, χοῦν, βοῦν· ταύτῃ καὶ ἡ κλεῖδα αἰτιατικὴ γενομένη κλεῖν περισπᾶται τῆς εὐθείας ὀξυνομένης. Αἱ ὑπὲρ μίαν συλλαβὴν ἰσοσύλλαβοι καὶ ὁμόχρονοι ταῖς εὐθείαις οὖσαι ὁμότονοί εἰσι, καλός καλόν, Ἑρμῆς Ἑρμῆν, χρυσοῦς χρυσοῦν, Ἀτρείδης Ἀτρείδην, ταχύς ταχύν, μῆνις μῆνιν, ἥπερ βραχυκαταληκτεῖ. τὰ γὰρ εἰς 'ιν' λήγοντα ἐν τῇ αἰτιατικῇ πάντα βραχέα ἐστὶν οἷον Εὔπολιν, Ἄλεξιν, ἔχιν, Θέτιν· οὕτω γοῦν καὶ μῆνιν, διὸ τὴν κνημῖδα καὶ σφραγῖδα οἱ Αἰολεῖς κνᾶμιν καὶ σφρᾶγιν λέγοντες μετὰ ὀλιγότητος συλλαβῶν συστέλλουσιν. εἶπον δὲ «ὁμόχρονοι» διὰ τὸ
No accusative ending in -α is accented with an acute; for τινά is accented with an acute to distinguish it from τίνα; hence νιφάδα, when apocopated, was raised in accent: «ἀλευόμενοι νίφα λευκήν». But Ἐρετριᾶ and Πειραιᾶ and Στειριᾶ and χοᾶ, by contraction of ε and α, take a circumflex. Every monosyllabic accusative ending in -ν takes a circumflex; but μῦν, μνᾶν, σῦν, ὗν, δρῦν, λῖν («ἐπί τε λῖν ἤγαγε δαίμων» (Λ 480)), γῆν, ναῦν, γραῦν have rejected the acute accent. θεῦν («τὴν θεῦν Ἄρτεμιν οἷ´ ἔπαθεν») is for τὴν θεὸν by contraction; likewise νοῦν, χοῦν, βοῦν; in the same way, κλεῖδα, when it becomes an accusative κλεῖν, takes a circumflex, while the nominative is accented with an acute. Accusatives of more than one syllable that are isosyllabic and of the same quantity as the nominatives are of the same accent, as καλός καλόν, Ἑρμῆς Ἑρμῆν, χρυσοῦς χρυσοῦν, Ἀτρεΐδης Ἀτρεΐδην, ταχύς ταχύν, μῆνις μῆνιν, which has a short final syllable; for all forms ending in -ιν in the accusative are short, as Εὔπολιν, Ἄλεξιν, ἔχιν, Θέτιν; so too μῆνιν; therefore the Aeolians, saying κνᾶμιν and σφρᾶγιν for κνημῖδα and σφραγῖδα, contract them by reducing the number of syllables. And I said “of the same quantity” because of the…