Abstract
Inflectional paradigms often deviate from an idealized one-to-one mapping between function (in terms of morphosyntactic feature values) and form. A single form may express multiple functions (syncretism). Or a form may express the ‘wrong’ function (deponency). In perhaps the most extreme case, defectiveness, there simply is no available form to express a morphosyntactically and lexically viable function. This chapter provides a concise survey of these phenomena, and discusses the implications they have for morphological models. On response is to enrich the morphosyntactic feature system and the rules that map these onto forms, the other is to develop a morphological component independent of the feature system.