Morphological variation in Spanish

•The study of morphological variation is complicated by the difficulty of finding an autonomous definition of morphology.•Morphological variation phenomena frequently are visible at the mapping between syntax and phonology or syntax and semantics.•Spanish exhibits a wide range of variation phenomena that affect, in one sense or the other, the morphological expression of units.•Both macro- and micro-parametric approaches have been proposed in order to capture morphological variation. In this article, we examine the current situation of studies that concentrate on the study of morphological variation in Spanish. We start discussing the place of morphology in current linguistic theory, and what its different aspects are, a question that is previous to the identification of the relevant phenomena. Section 2 provides an overview of the situation of variationist studies in Spanish, and Section 3 presents the main morphological variation phenomena. Section 4 introduces in the picture the different approaches to variation that are currently discussed in the relevant literature. We close with an overview of the articles included in this volume.