Metaphony and diphthongization in southern Italy: reconstructive implications for sound change in early Romance

Both diphthongization and metaphony per se, and the interaction between the two, are among the most investigated topics in Romance historical linguistics. In this paper, I suggest that the two do not originally belong together, in the sense that a) the so-called Romance diphthongization, which affected PRom /ɛ ɔ/ in most Romance languages, was not originally sensitive to the quality of the final unstressed vowel; and b) the different types of metaphony observed across (Italo-)Romance, often involving diphthongization, are most economically explained as changes which all first arose as assimilatory raising, not as diphthongization. These data provide an interesting case study in what one might call the division of labor of phonetics and (morpho)phonology for the explanation of sound change. In this connection, experimental phonetic evidence from Southern Italian dialects will prove crucial.