How did Oscan differ from Latin in its sound changes and vocabulary?

Oscan and Latin, while both Italic languages, diverged significantly in their phonology and vocabulary due to independent development.12

Sound Changes

• Labiovelar Stops: The Indo-European labiovelar stop $k^w$ evolved into qu in Latin, but became p in Oscan (e.g., Latin quis vs. Oscan pis "who").2
• Vowel Shifts: Oscan tended to lose short vowels in noninitial syllables, whereas Latin reduced them. Additionally, Oscan underwent specific shifts such as $\overline{o}$ to u, $\overline{e}$ to i, and final $\overline{a}$ to o (e.g., Latin dōnum vs. Oscan dúúnúm "gift").2
• Aspirated Consonants: While both languages replaced initial Indo-European voiced aspirates with the fricative f, they differed in internal positions. Latin often developed voiced stops (like b), while Oscan developed the voiceless spirant f (e.g., Latin liberi vs. Oscan loufro- "free").2

Vocabulary

Oscan and Latin often utilized distinct terminology, particularly regarding urban and political life, suggesting they developed independently before contact. For example, Latin used porta for "gate," while Oscan used veru; for "state," Latin used populus or civitas, while Oscan used touto. Political titles also differed, with Latin using consul and Oscan using meddíss.3