Rules for aspiration (dasea) and psilosis of vowels before ρ (rho) and other consonants (γ, μ, π, σ), with Attic variations and examples.
Πᾶν φωνῆεν πρὸ δασέος καὶ τοῦ 'ρ' ψιλοῦται, ὀφρῦς, ἀφρός, ὄφρα, ἀθρῶ «ἡ δ´ οὔτ´ ἀθρῆσαι δύνατο» (Od. τ 478). τὸ ἁθρόος, ὅτε ἐπιτατικὸν ἔχει τὸ 'α', δασύνεται παρ´ Ἀττικοῖς. Πᾶν φωνῆεν εἰς 'ρ' λῆγον ἐπιφερομένου δασέος ψιλοῦται, ἄρχω, ἔρχομαι, ὄρχος, ὀρφανός, ὔρχα τὸ ταριχηρὸν ἀγγεῖον. Ἀττικοὶ δὲ δασύνουσι τὸ εἱρκτή εἱρχθῆναι. * Τὰ φωνήεντα καταλήγοντα εἰς τὸ 'ρ' ἐπιφερομένου τοῦ 'σ' ψιλοῦσθαι φιλεῖ, ἄρσαντες, Ἀρσινόη «ἐς δὲ σταθμοὺς ἄρσε» (Od. φ 45), ὄρσας «ὄρσεο κυλλοπόδιον» (Il. Φ 331). ταύτῃ ἀναλογώτερον τὸ ἕερσα τρισυλλάβως. * Τὰ βραχυνόμενα φωνήεντα καταλήγοντα εἰς 'ρ' ἐπιφερομένου τοῦ 'μ' δασύνεται, ὅρμος, ἅρμα, Ἑρμῆς, ὁρμαθός. ἔνθεν ἡ πλείων χρῆσις τὸ ἁρμοῖ δασύνει. τὸ μέντοι ἄρμενον καὶ ὄρμενον ψιλὸν πνεῦμα ἀνεδέξατο. καὶ τὸ ἕρματα (Α 486) εἰ καὶ ἐκ τοῦ ἐρείσματα, οὐ ψιλοῦται, ὥς τινες. * Τὰ 'α' καὶ τὸ 'ε' καταλήγοντα εἰς τὸ 'ρ' ἑπομένου τοῦ 'π' δασύνεσθαι ἤθελεν, ὡς ἔχει τὸ ἅρπη, ἁρπάζω, ἁρπαλέος, ἑρπετόν, ἑρπύζω, Ἅρπυια καὶ τὸ ὄρπηξ τούτοις ἐξομοιοῦντές τινες ἠθέλησαν δασύνειν, οἷς οὐκ ἐπείσθη ἡ παράδοσις, ἀλλὰ τῇ ἐτυμολογίᾳ· παρὰ γὰρ τὸ ὄρω πλεονασμῷ τοῦ 'π' γεγένηται τὸ ὄνομα. * Τὸ 'ε' καὶ 'α' πρὸ τοῦ 'ρ' φωνήεντος ἐπιφερομένου ψιλοῦται, ἔρος, ἄρω. Πᾶν φωνῆεν πρὸ τοῦ 'γ' ψιλοῦται, πλὴν τοῦ 'η' καὶ 'υ', ἀγορά, ἄγαν, ὠγύγιος, ἐγγύς. τὸ μέντοι ἁγνός καὶ ἅγιος τοῦ ἅζω ῥήματος τὴν δασεῖαν ἐφύλαξαν. * Πᾶν φωνῆεν καταλῆγον ἢ εἰς 'ν' ἢ εἰς 'γ', τῆς ἑξῆς συλλαβῆς ἀρχομένης
Every vowel before a rough breathing and before a smooth 'ρ' is pronounced with smooth breathing: ὀφρῦς, ἀφρός, ὄφρα, ἀθρῶ—“but she was not able to look” (Od. τ 478). But ἁθρόος, when it has an intensive 'α', is given rough breathing among the Attic writers.
Every vowel ending in 'ρ', when a rough breathing follows, is pronounced with smooth breathing: ἄρχω, ἔρχομαι, ὄρχος, ὀρφανός, ὔρχα, the vessel for salted fish. The Attic writers, however, give rough breathing to εἱρκτή, εἱρχθῆναι.
Vowels ending in 'ρ', when 'σ' follows, tend to be pronounced with smooth breathing: ἄρσαντες, Ἀρσινόη—“and to the stations he lifted” (Od. φ 45), ὄρσας—“rise, club-footed one” (Il. Φ 331). In accordance with this, ἕερσα is more regular when trisyllabic.
Vowels that are shortened and end in 'ρ', when 'μ' follows, are given rough breathing: ὅρμος, ἅρμα, Ἑρμῆς, ὁρμαθός. Hence the more common usage gives rough breathing to ἁρμοῖ. But ἄρμενον and ὄρμενον have admitted smooth breathing. And ἕρματα (Α 486), even if it is from ἐρείσματα, is not pronounced with smooth breathing, as some say.
'α' and 'ε' ending in 'ρ', when 'π' follows, tended to be given rough breathing, as in ἅρπη, ἁρπάζω, ἁρπαλέος, ἑρπετόν, ἑρπύζω, Ἅρπυια. And some, assimilating ὄρπηξ to these, wished to give it rough breathing; but the tradition did not persuade them, rather the etymology: for the noun has been formed from ὄρω by addition of 'π'.
'ε' and 'α' before a vowel with 'ρ' following are pronounced with smooth breathing: ἔρος, ἄρω.
Every vowel before 'γ' is pronounced with smooth breathing, except 'η' and 'υ': ἀγορά, ἄγαν, ὠγύγιος, ἐγγύς. But ἁγνός and ἅγιος have preserved the rough breathing of the verb ἅζω.
Every vowel ending either in 'ν' or in 'γ', when the following syllable begins…