Parts of Speech are a central aspect of linguistic theory and analysis. Though a long-established tradition in Western linguistics and philosophy has assumed the validity of Parts of Speech in the study of language, there are still many questions left unanswered. For example, should Parts of Speech be treated as descriptive tools or are they to be considered universal constructs? Is it possible to come up with cross-linguistically valid formal categories, or are categories of language structure ultimately language-specific? Should they be defined semantically, syntactically, or otherwise? Do non-Indo-European languages reveal novel aspects of categorical assignment? This volume attempts to answer these and other fundamental questions for linguistic theory and its methodology by offering a range of contributions that spans diverse theoretical persuasions and contributes to our understanding of Parts of Speech with analyses of new data sets.
These articles were originally published in Studies in Language 32:3 (2008).

Luca Alfieri, in Studies in Language 37(2): 425-434, 2013:
In sum, the book is an important contribution to the current debate on the PoS. It is highly recommended to scholars that have a specific interest in PoS research, and may be suggested to others. Furthermore, the link between PoS theory and historical linguistics makes the book (and, generally, the literature on PoS typology) a good buy for libraries interested in Indo-European and Semitic linguistics.