Zero elements are used by several theories in morphology and syntax as analytical tool, but the question of whether phonologically empty elements should be structurally present or not has been a controversial issue from the very beginning. In addition to analyses that work with zero, there are also a whole series of works that explicitly reject a description with zero or allow them only under restricted circumstances. This volume aims at getting a more complete picture of zero elements as a theoretic construct, its empirical necessity and its nature in different components of grammar by focusing on Romance languages. The volume presents multi-facetted viewpoints and methodologies, such as formal theoretic and data-based ones, addressing researchers, advanced students and everyone interested in linguistics. Furthermore, this volume deals with various Romance languages and varieties, such as Catalan, (Old and Modern) French, Italian and Sicilian, (Brazilian and European) Portuguese, and Spanish.