Mark C. Baker investigates the fundamental nature of nouns, verbs, and adjectives. He claims that the various superficial differences found in particular languages have a single underlying source which can be used to provide better definitions of these parts of speech . The new definitions are supported by data from languages from every continent. Baker’s book argues for a formal, syntax-oriented, and universal approach to the parts of speech, as opposed to the functionalist, semantic, and relativist approaches that have dominated the subject.