Abstract
Perfective stem allomorphy and stress are morphological traits which interact in complex ways in Romance verbal inflection. This article surveys the whole range of variation of these traits across Romance varieties, typologizes the observed interactions between the two, and examines attested and unattested possibilities. A comparison between the modern-day and the original Latin systems suggests that there is a strong pan-Romance bias against having verbs with a concrete combination of properties: perfective root-stress and no perfective stem alternation. This is a combination of traits that would have frequently resulted in diagonal syncretisms between past and present given the phonological changes attested in the daughter languages. Homophony avoidance (and the adaptive-discriminative role of morphology more generally) are therefore argued to motivate the observed bias.
Keywords: change biases; diachrony; homophony; morphology; predictability; syncretism