Phonology
Phonological characteristics of older Latin:
- Preservation of original PIE (Proto-Indo-European) thematic case endings -os and -om (later -us and -um).
- Most original PIE diphthongs were preserved in stressed syllables, including /ai/ (later ae, but pronunciation unchanged); /ei/ (later ī); /oi/ (later ū, or sometimes oe); /ou/ (from PIE /eu/ and /ou/; later ū).
- Intervocalic /s/ (pronounced ) preserved up through 350 BC or so, at which point it changed into /r/ (called rhotacism). This rhotacism had implications for declension: early classical Latin, honos, honoris (from honos, honoses); later Classical (by analogy) honor, honoris ("honor"). Some Old Latin texts preserve /s/ in this position, such as the Carmen Arvale's lases for lares. Later instances of /s/ are mostly due either to reduction of early /ss/ after long vowels or diphthongs; borrowings; or late reconstructions.
- Many unreduced clusters, e.g. iouxmentom (later iūmentum, "beast of burden"); losna (later lūna, "moon") < *lousna < */leuksnā/; cosmis (later cōmis, "courteous"); stlocum, acc. (later locum, "place").
- /dw/ (later b): duenos (later bonus, "good"), in the famous Duenos inscription.
- Final /d/ in ablatives (later lost) and in third-person secondary verbs (later t).
Read more about this topic: Old Latin