Monophthongs

Diphthong

/au̯/ appears to be the only phonemic diphthong that can be reconstructed.^[1]

Phonetics

• Vowels were lengthened in stressed open syllables.^[2]
• Stressed /ɛ ɔ/ may have yielded incipient diphthongs like [e͡ɛ o͡ɔ] in metaphonic conditions.^{[3][lower-roman 1]}
  • Metaphony, if it is to be projected to Proto-Romance, may have initially been limited to open syllables. That is, it would have targeted allophonically lengthened /ɛ ɔ/.^[4]

Constraints

• /ɛ ɔ/ did not occur in unstressed position.^[5]
• /i u/ did not occur in the second syllable of words with the structure ˌσσˈσσ.^{[6][lower-roman 2]}

Palatalized consonants

• There is scholarly disagreement over whether palatalization was phonemic in Proto-Romance.^{[8][lower-roman 3]}
• Palatalized consonants tended to geminate between vowels. The extent of this varied by consonant.^{[9][lower-roman 4]}
• /tʲ/ would have been an affricate like [t͡sʲ]^[10] or [t͡zʲ].^[11]

Phonetics

• /sC/ in word-initial position was assigned a prop-vowel [ɪ], as in /ˈstare/ [ɪsˈtaːɾe].^{[12][lower-roman 5]}
• /ɡn/ was likely [ɣn] at first, with later developments varying by region.^{[13][lower-roman 6]}
• /d ɡ/ might have been fricatives or approximants between vowels.^[14]
• /ll/ might have been retroflex.^{[15][lower-roman 7]}
• /f/ might have been bilabial.^[16]

Constraints

• /b/ did not occur in intervocalic position.^{[17][lower-roman 8]}

Positive

Comparative

For the most part, the typical way to form a comparative would have been to add magis or plus (‘more’) to a positive adjective. A few words were inherited with a comparative suffix -ior. Their inflections can be reconstructed as follows:^[21]

Superlative

Superlatives would have been formed by adding definite articles to comparatives.^[22]

Personal

Interrogative/relative

As follows:^[25]

Present

Preterite

Participles