Wagiman is an Australian Aboriginal language spoken by about ten people in the top end of the Northern Territory. It possesses an unusual open class of words which Wilson calls 'coverbs'. Coverbs are responsible for conveying a wide range of mostly verbal and adjectival meanings. They are most frequently paired with an inflecting verb from a closed class to form a complex predicate: the coverb and inflecting verb jointly determine the verbal semantics and argument structure of the clause. This book provides a descriptive and analytical account of the behaviour of coverbs in Wagiman, especially their role in complex predicate formation. The author seeks to discover what governs which pairings of coverbs and inflecting verbs are possible, and how the meaning of the whole can be derived from the meanings of the parts. Wilson pursues a formal account of Wagiman complex predicates within Lexical Functional Grammar, seeing complex predicate formation as the fusion of Lexical Conceptual Structures.