In A Grammar of Lopit, Jonathan Moodie and Rosey Billington provide the first detailed description of Lopit, an Eastern Nilotic language traditionally spoken in the Lopit Mountains in South Sudan. Drawing on extensive primary data, the authors describe the phonology, morphology, and syntax of the Lopit language. Their analyses offer new insights into phenomena characteristic of Nilo-Saharan languages, such as ‘Advanced Tongue Root’ vowel distinctions, tripartitite number marking, and marked-nominative case systems, and they uncover patterns which are previously unattested within the Eastern Nilotic family, such as a three-way contrast in aspect, number marking with the ‘greater singular’, and two kinds of inclusory constructions. This book offers a significant contribution to the descriptive and typological literature on African languages.