Description of accentual and vowel changes in words ending in -ος/-ωος with a written or added iota (ἰ), showing contraction, vowel shifts (ε→o→ω), accent shifts (properispomenon, proparoxytone, oxytonization), and examples of ethnics and place names (πατρῷος, ἡρῷος, Ἀχελῷος, ὀρεσκῷος, Ἄθωος).
Τὰ εἰς 'ος' καθαρὸν ὑπὲρ δύο συλλαβὰς τῷ 'ω' μετὰ 'ι' προσγεγραμμένου παραληγόμενα προπερισπᾶται, πατρῷος, ἡρῷος καὶ Ἡρῷος, ἠῷος, Ἀχελῷος ποταμὸς Ἀκαρνανίας ἀπὸ Ἀχελῴου ἐλθόντος ἐκ Θετταλίας μετὰ Ἀλκμαίωνος καὶ τὸ ἐθνικὸν ὁμοφώνως, αἰδῷος, Μινῷος, Ἐλβῷος, Σαρδῷος, Πυθῷος, Ληθῷος, Ἰνδῷος, Γελῷος ὁ οἰκῶν Γέλαν πόλιν Σικελίας ἴσως ἀπὸ τοῦ γέλως. ὀρεσκῷος ἀπὸ τοῦ κείω τοῦ σημαίνοντος τὸ κοιμῶμαι καὶ τὸ ὄρος γέγονεν ὀρέσκειος καὶ τροπῇ τοῦ 'ε' εἰς 'ο' ὀρέσκοιος καὶ ἐκτάσει τοῦ 'ο' εἰς 'ω' καὶ μεταθέσει τοῦ τόνου ὀρεσκῷος καὶ μένει τὸ 'ι' προσγεγραμμένον. προπερισπᾶται δὲ διὰ τὸν χαρακτῆρα. τὸ δὲ κολῳός ὀξύνεται ἀπὸ τοῦ κολοιός. τὸ μέντοι λαγωός καὶ πατρωός ὁ ἐν τῇ συνηθείᾳ πατρυιός ὀξύνονται, ὅτι οὐκ ἔχουσι τὸ 'ι' προσγεγραμμένον. τὸ δὲ Ἄθωος τοπικὸν χωρὶς τοῦ 'ι' προπαροξύνεται καὶ τὸ Ἀκρόθωοι πόλις ἐπὶ τῆς ἄκρας τοῦ Ἄθω καὶ ἔθνος. τὸ δὲ δηλοῦν τὸ ἀζήμιον προπερισπᾶται ��αὶ διὰ τοῦ 'ι', ἐκ τῆς θῳῆς.
Nouns in pure -ος of more than two syllables, whose penult is ω with iota subscript, are accented with a circumflex on the antepenult: πατρῷος, ἡρῷος and Ἡρῷος, ἠῷος, Ἀχελῷος, a river of Acarnania, from Achelous who came from Thessaly with Alcmaeon, and the ethnic name likewise; αἰδῷος, Μινῷος, Ἐλβῷος, Σαρδῷος, Πυθῷος, Ληθῷος, Ἰνδῷος, Γελῷος, the inhabitant of Gela, a city of Sicily, perhaps from γέλως. ὀρεσκῷος, from κείω meaning “I lie down,” and ὄρος, has become ὀρέσκειος, and by change of ε to ο, ὀρέσκοιος, and by lengthening of ο to ω and transposition of the accent, ὀρεσκῷος; and the iota subscript remains. It is accented with a circumflex on the antepenult because of its form. But κολῳός is accented acute, from κολοιός. However λαγωός and πατρωός—commonly πατρυιός—are accented acute, because they do not have iota subscript. But Ἄθωος, a place-name without iota, is accented with an acute on the antepenult, and likewise Ἀκρόθωοι, a city on the headland of Athos, and a people. But the word meaning “harmless” is accented with a circumflex on the antepenult, also with iota, from θῳή.