Deriving inflectional irregularity

International audienceConventional wisdom holds that productive morphology is regular morphology. Drawing evidence from French, we argue that the description of many lexeme formation processes is simplified if we hold that a productive rule may give rise to inflectionally irregular lexemes. We argue that the notion of a stem space allows for a straightforward description of this phenomenon: each lexeme comes equipped with a vector of possibly distinct stems, which serve as bases for inflectional form construction. The stem space is structured by default relations which encode the regular pattern of inflection; (partial) irregularities occur when a lexeme specifies a stem space violating the default relations. Derived irregularity is then the effect of a productive lexeme formation rule which specifies an irregular stem space for its output