Phonological rules for vowel length and accent/stress in Greek nouns and adjectives: when final syllables end with certain endings ( -α, -αρ, -υλον, -ας, -ος, -ιν, -αι, -ω ) affected by dialectal variation (Attic, Aeolic, Doric) and contexts (diminutives, accusative, disyllabic forms). Examples given for extension vs contraction of alpha, ypsilon, iota, other vowels; notes on specific words and dialectal practices.
περισπωμένην τοῦ πᾶς ἀρσενικοῦ ἐκτείνει τὸ 'α'. ὅταν μέντοι τὸ πᾶν δισυλλάβως λέγηται, τότε ἕξει τὸ 'α' συνεσταλμένον, σύμπαν, ἅπαν. εὕρηται παρ´ Ἀθηναίοις ἐκτεῖνον τὸ 'α'. Τὰ διὰ τοῦ 'αριον' ὑποκοριστικὰ παρὰ τοῖς παλαιοῖς Ἕλλησι συστέλλει τὸ 'α', ἱππάριον, πλοιάριον, φυτάριον. ἡ μέντοι νῦν συνήθεια ἀπὸ τῆς τῶν Ῥωμαίων διαλέκτου πολλὰ ἐπίσταται διὰ τοῦ 'αριον' ἐκτεταμένα, σουδάριον λέγουσα καὶ κελλάριον. * Τὰ διὰ τοῦ 'υλον' οὐδέτερα δισύλλαβα καθαρὰ μονογενῆ ἐκτείνει τὸ 'υ' οἷον σκῦλον, φῦλον, κῦλον. σεσημείωται τὸ ξύλον. * Τὰ εἰς 'ας' λήγοντα οὐδέτερα καὶ βαρύνεται καὶ συστέλλονται, κρέας, τέρας, δέπας, κέρας. Τὰ εἰς 'ος' οὐδέτερα δισύλλαβα ἔχοντα πρὸ τοῦ τέλους τὸ 'α', συνεσταλμένον αὐτὸ ἔχει, δάος, φάος, χάος, ἄχος, σάκος, βάρος, πάθος, κράτος, θράσος. πλὴν τοῦ φᾶρος «φᾶρος μέν οἱ πρῶτον ἐϋπλυνὲς ἠδὲ χιτῶνα» (π 173)· οἱ μέντοι τραγικοὶ ἐπίσης ἐκτείνουσι τοῦ προκειμένου ὀνόματος τὸ 'α' καὶ συστέλλουσι. καὶ τοῦ πρᾶγος· τοῦτο δὲ παρὰ τὸ πρήσσω καὶ πράσσω γενόμενον συνεκτεινόμενον ἔσχε τῷ ῥήματι τὸ 'α'. τὸ δὲ μᾶκος ἐστὶ κατὰ διάλεκτον ἐκ τοῦ μῆκος. * Πᾶσα αἰτιατικὴ ἀπαθὴς εἰς 'α' λήγουσα συστέλλεσθαι θέλει, Ἀλκμᾶνα, ποιμένα, Ἕκτορα, θώρακα, Αἴαντα, Ἀχιλλέα, βασιλέα. Ἀττικοὶ μέντοι ἐκτείνουσι τὰς ἀπὸ τῶν εἰς 'ευς', Ἀτρέα λέγοντες καὶ ἱερέα. πρόσκειται ἀπαθὴς διὰ τὸ χοᾶ καὶ Ἐρετριᾶ καὶ Πειραιᾶ καὶ Στειριᾶ. * Τὰ εἰς 'ιν' λήγοντα ἐν τῇ αἰτιατικῇ πάντα βραχέα ἐστίν, οἷον Εὔπολιν, Ἄλεξιν, ἔχιν, Θέτιν. οὕτω γοῦν καὶ μῆνιν, διὸ τὴν κνημῖδα καὶ σφραγῖδα οἱ Αἰολεῖς κνᾶμιν καὶ σφρᾶγιν λέγοντες μετὰ ὀλιγότητος συλλαβῶν συστέλλουσιν. Αἱ εἰς 'αι' λήγουσαι εὐθεῖαι πληθυντικαὶ ἐκτείνουσαι τυγχάνουσι τὸ 'α' τῶν αἰτιατικῶν, Σκύθαι Σκύθας, καλαί καλάς, οἱ δὲ Δωριεῖς συστέλλουσι Σκύθας, ναῦτας. * Τὰ εἰς 'ω' λήγοντα καθαρὰ βαρύτονα ῥήματα, ὑπὲρ δύο συλλαβὰς ὑπάρχοντα, εἰ παραλήγοιτο τῷ 'ι', μόνῳ ἐκτεταμένῳ αὐτῷ παραλήγεται, χωρὶς εἰ μὴ σύνθετα εἴη ἢ κατ´ ἔλλειψιν τοῦ 'ζ', κυλίω, ἀλίω, μηνίω, δηρίω, κονίω, ἰδίω. τὸ δὲ ἐσθίω συστέλλει τὸ 'ι'. ἐφυλαξάμην δὲ σύνθετα διὰ τὸ ἀτίω τήν τε ἔλλειψιν τοῦ 'ζ' διὰ τὸ μαστίω. τὸ δὲ δειδίω οὐ ῥητόν. τὸ δὲ κηκίω ἐκ διπλασιασμοῦ «πολλὴ δ´ ἀνεκήκιεν ἅλμη».
The circumflex of πᾶς in the masculine lengthens the α. But when πᾶν is said disyllabically, then it will have the α shortened: σύμπαν, ἅπαν. It is found among the Athenians lengthening the α. The diminutives in -αριον among the ancient Greeks shorten the α, e.g. ἱππάριον, πλοιάριον, φυτάριον. The present usage, however, from the dialect of the Romans, recognizes many forms in -αριον with the α lengthened, saying σουδάριον and κελλάριον.
The neuters in -υλον, disyllabic, pure, and of one gender, lengthen the υ, e.g. σκῦλον, φῦλον, κῦλον. ξύλον is noted as an exception.
The neuters ending in -ας are both barytone and shortened: κρέας, τέρας, δέπας, κέρας. The disyllabic neuters ending in -ος that have α before the ending have it shortened: δάος, φάος, χάος, ἄχος, σάκος, βάρος, πάθος, κράτος, θράσος—except φᾶρος: «φᾶρος μέν οἱ πρῶτον ἐϋπλυνὲς ἠδὲ χιτῶνα» (π 173). The tragedians, however, likewise both lengthen and shorten the α of the aforesaid noun. And likewise with πρᾶγος: this, having been formed from πρήσσω and πράσσω, had the α lengthened along with the verb. But μᾶκος is, according to dialect, from μῆκος.
Every uninflected accusative ending in -α wants to be shortened: Ἀλκμᾶνα, ποιμένα, Ἕκτορα, θώρακα, Αἴαντα, Ἀχιλλέα, βασιλέα. The Attics, however, lengthen those derived from nouns in -ευς, saying Ἀτρέα and ἱερέα. “Uninflected” is added because of χοᾶ and Ἐρετριᾶ and Πειραιᾶ and Στειριᾶ.
Those ending in -ιν in the accusative are all short, e.g. Εὔπολιν, Ἄλεξιν, ἔχιν, Θέτιν. Thus also μῆνιν; for which reason the Aeolians, saying κνᾶμιν and σφρᾶγιν for κνημῖδα and σφραγῖδα, shorten them with fewer syllables. The nominative plurals ending in -αι happen to lengthen the α of the accusatives: Σκύθαι—Σκύθας, καλαί—καλάς; but the Dorians shorten, Σκύθας, ναύτας.
The pure barytone verbs ending in -ω, being more than two syllables, if they have ι in the penult, have the penult only with that ι lengthened—unless they are compounds or are formed by loss of ζ: κυλίω, ἀλίω, μηνίω, δηρίω, κονίω, ἰδίω. But ἐσθίω shortens the ι. I have excepted compounds because of ἀτίω, and loss of ζ because of μαστίω. But δειδίω is not in use. And κηκίω is from reduplication: «πολλὴ δ´ ἀνεκήκιεν ἅλμη».