This work is a reference grammar of Hup, a member of the Nadahup family (also known as Makú or Vaupés-Japura), which is spoken in the fascinatingly multilingual Vaupés region of the northwest Amazon. This detailed description and analysis is informed by a functional-typological perspective, with particular reference to areal contact and grammaticalization. The grammar begins with an introduction to the cultural and linguistic background of Hup speakers, gives an overview of the phonology, and follows this with chapters on morphosyntax (nominal morphology, verbs and verb compounding, tense, aspect, modality, evidentiality, etc.); it concludes with discussions of negation, the simple clause, and clause combining. A number of features of Hup grammar are typologically significant, such as its strategy of inversion in question formation, its system of Differential Object Marking, and its treatment of possession. Hup also exhibits several highly unusual paths of grammaticalization, such as the development of a verbal future suffix from the noun ‘stick, tree’. The book also includes a selection of texts and a CD-ROM with audio files.