This volume considers and examines some of the phenomena that have led languages to be considered "ergative". Languages considered "ergative" have only been sparsely studied, and many fundamental questions in their analysis seem at best incompletely answered. This volume fills that void by focusing on some of the basic issues: when ergativity should be analyzed as syntactic or morphological; whether languages can be divided into two classes of syntactically and moprhologically ergative languages, and if so, where the division should be drawn; and whether ergative arguments are always core roles or not.