Ngalakgan is a non-configurational, polysynthetic, and agglutinative language of the Gunwinyguan family. "Word Structure in Ngalakgan" is the first major theoretical work on the phonology and morphology of this intriguing Australian language in twenty years.Baker demonstrates that Optimality Theory must take account of differences in the productivity of morphological relations in the input, in order to maintain the simplest analysis. This volume examines the syllabification of the language, among other aspects, arguing that Ngalakgan has a quantity-sensitive stress system that is hitherto undescribed and that contradicts the predictions of current Moraic Theory.