This volume is a study of coordination, i.e. structures with conjunctions such as and, but, and or. These are important words in their constructions, rather than being unimportant and superfluous, because they have many properties in common with categories such as verbs and prepositions. DrJohannessen has analysed data from thirty-three languages, many of them unrelated, and has found striking similarities. She focuses in particular on `unbalanced coordination' (UC), that is, coordination in which the conjuncts differ with respect to crucial grammatical features such as case and word order. UC occurs in many of the languages in the study, and provides evidence for an analysis of overt, as well ascovert, conjunctions as heads in an X-bar theoretical framework. Specifically, there is a strong correlation between the order of conjunctions and abnormal conjuncts and that of heads and complements generally in the languages that have UC. Dr Johannessen also considers extraordinary balanced coordination, in which both conjuncts are abnormal. This phenomenon provides additional evidence for conjunctions being heads. She gives a comprehensive account of coordination in general, including extraction, coordination categories, multiplecoordination, and 'discontinuous conjunctions'. SERIES DESCRIPTION Oxford Studies in Comparative Syntax Series Editor: Richard S. Kayne The growing sophistication of syntactic theory is making it possible to achieve an increasingly precise characterization of syntactic differences among languages. By shedding light on the nature of syntactic variation, the books in this series will also contribute to our understanding of that whichis syntactically variant, i.e. those facets of syntax that can be construed as reflecting properties of universal grammar.