I expressed the notion some years ago that Italian (and general Romance) ' ie', 'uo' = Vulgar Latin 'ē', 'ō' was originally conditioned by a following ' i' or ' u ' as it still is in some dialects: 'vieni', 'buonu', 'buoni'. First it would have been extended by conceptual analogy: 'viene', 'buona' until a point was reached where no such support was necessary: 'pietra', 'ruota'. Forms like 'bene', 'bove' (Plur. 'buoi'), 'nove' (in contrast to 'nuovo') would simply represent the last unconquered positions. I do not know whether my assumption of purely phonetic analogy is an entirely new thing […] In any case, I am not about to set up a new antithesis […]. (pp. 45-46)
- Schuchardt (1972)