The Paradigmatic Dimension of Stem Allomorphy in Italian Verb Inflection

This paper is concerned with a detailed analysis of stem allomorphy in Italian Conjugation, carried out from a phonological and paradigmatic perspective. In theory, one would expect these two complementary viewpoints to take care of neatly separable classes of phenomena. In fact, the two dimensions turn out to be interlocked in a complex way, to define a grammatical continuum ranging from minor phonological processes to full suppletion. A formal descriptive framework is proposed here, whereby several insights into the structure of inflectional paradigms (Matthews 1974, Carstairs 1987, Wurzel 1989, Stump 1991, Aronoff 1994) are dealt with from a unifying, purely morphological perspective. In this framework, the structure of a verb paradigm is characterised in terms of a distribution of slots into a number of equivalence classes, or set partition, where each equivalence class is associated with a morphologically distinct stem root. It is shown that, in Italian, a few set partitions account for the structure of all Italian verb paradigms, whether regular or less regular. Moreover, all these partitions are mutually related homomorphically. This well-behaved family of distributions tightly constrains stem allomorphy at an appropriate level of abstraction, independently of whether the origin of allomorphy is morpho-phonological or purely morphological, showing the superiority of the obtained generalisations over more traditional syntagmatic accounts.