Basque is a language of central importance to linguists because it is a 'language isolate,' a rare type of language that is typologically 'alone' and cannot be classified as a part of any language family. Language isolates remain somewhat a mystery, and this book aims to provide an important piece of the puzzle, by both exploring the structure of Basque and shedding new light on its unique place within the languages of the world. It meticulously examines various properties of Basque, including the alignment of intransitive verbs, the introduction of dative arguments, the nature of psych predicates, the causative/inchoative alternation, impersonals, and morphological causatives. By doing so, it presents a comprehensive overview of Basque's intricacies within the realm of argument structure alternations and voice. In its final chapter, it provides an introduction to potential formal analyses of the topics discussed, paving the way for future research in the field. This title is part of the Flip it Open programme and may also be available open access. Check our website Cambridge Core for details.