Samar Sinha presents pioneering research into the grammatical properties of Indian Sign Language (ISL), a language used by members of the Deaf community in India. This detailed and well-illustrated study describes the grammar of ISL and is supplemented by comparative and theoretical analyses in the core areas of sublexical structure, morphology, and syntax. Sinha offers a field-based, comprehensive analysis that covers topics such as sign formation parameters, syllable structure, sonority hierarchy, semantics of space, pluralization strategies, phi-features, indexing and localization, agreement, and word order. He provides a description of the Indian Deaf community that serves to frame his analysis of ISL and highlights the need for greater awareness and acknowledgment of the language and its users. The lack of research on ISL in Indian academia has slowed efforts toward the standardization of ISL and the development of pedagogical materials. This work adds to the growing understanding of natural human language in general and ISL in particular. It also contributes to the empowerment of the Deaf community in India and will strengthen the efforts carried out by d/Deaf activists and researchers.