Established in the early 1980s, Word Grammar is the first theory of grammar that was cast in the terms of cognitive linguistics. This book surveys the groundbreaking contribution of WG to a number of disciplines both within and outside of linguistics. It illustrates the benefits of thinking beyond traditional phrase-structural notions of syntax, and beyond encapsulated theories of cognition, by exploring how key problems in theoretical linguistics and historical linguistics can be approached from alternative perspectives. It provides examples of how theoretical linguistic notions and constructs of WG can be applied to bilingual language use, as well as a variety of typologically different languages including English, Chinese, German and Swedish. It also explores the relationship between language and social cognition and dependency distance as a universal measure of syntactic complexity. It is essential reading for linguists seeking creative ideas on how to advance explanations of language, language variation and change.