This volume presents the first comprehensive grammatical description of B ahr t (also known as Ba hari), one of the least documented and most endangered modern South Arabian languages, spoken by a once remote and marginalised community in southern Oman. Drawing on decades of fieldwork by Miranda Morris and more recent linguistic analysis by Fabio Gasparini, the grammar offers a detailed account of the phonology, morphology, syntax, and sociolinguistic context of this unique language. The small B ahr t-speaking community, once coastal fisherfolk with a distinct identity, now only speaks Arabic. The grammar reflects not only a linguistic system in decline, but also a cultural heritage at risk of disappearing. Special care has been taken to present the data clearly and typologically in order to make it accessible to readers beyond the field of Semitic studies. Rich in examples and based on extensive recordings and notes, this grammar is an invaluable resource for linguists, anthropologists and historians interested in endangered languages, Semitic linguistics, and Arabian Peninsula ethnography.