Even though null subjects have been extensively studied in the past four decades, there is a growing interest in partial null subject languages (e.g. Finnish) and a subtler classification of null subject phenomena overall. This volume aims at contributing to this trend, focusing on Slavic and Finno-Ugric groups, with some extension to Baltic and Samoyedic languages. Interestingly, these groups offer an impressive array of macro- and microvariation. Moreover, given an increasing interest towards the internal structure of the pronominal elements and the role of various types of topics in the left periphery of the sentence structure, the enterprise taken up in this book is to investigate lexical and null, referential and generic subjects in order to understand and compare their feature composition, licensing conditions, and structural properties. Rather than trying to squeeze the studied languages into a predefined set of parameters, this volume highlights some properties that may lead to a refinement of the existing generalizations. It brings together contributors from both generative and typological traditions and will be of interest to any researcher willing to investigate argument-drop in a wider crosslinguistic perspective.