Latin and Faliscan have several features in common with other Italic languages:
The late Indo-European diphthong /*eu/ evolved into ou.[2]
The late Indo-European /*ə/ from vocalic laryngeals evolved into a.[3]
The Indo-European syllabic liquids /*l̥,*r̥/ developed an epenthetic vowel o, giving Italic ol, or.[4]
The Indo-European syllabic nasals /*m̥,*n̥/ developed an epenthetic vowel e, giving Italic em, en.[5]
Word-initial aspirated stops from Indo-European were fricativised: /*bʰ,*dʰ,*gʰ,gʷʰ/ > f, f, h, f.[6]
The sequence /*p...kʷ/ was assimilated into kʷ...kʷ (Proto-Indo-European *penkʷe 'five' > Latin quinque).[7]
Latin and Faliscan also have characteristics not shared by other branches of Italic. They retain the Indo-European labiovelars /*kʷ,*gʷ/ as qu-, gu- (later becoming velar and semivocal), whereas in Osco-Umbrian they become labial p, b. Latin and Faliscan use the ablative suffix -d, seen in med ("me", ablative), which is absent in Osco-Umbrian. In addition, Latin displays evolution of ou into ū, though this happens later than the Latino-Faliscan era, occurring around the 2nd century BCE (Latin lūna < Proto-Italic *louksnā < PIE *lówksneh₂ "moon").