This volume presents a reference grammar of Jambi Malay as spoken in villages across the river from Jambi City, Sumatra—especially Tanjung Raden and Mudung Darat. The Tanjung Raden variety represents Baso Seberang ‘language from across’, a term used by local speakers, while Mudung Darat, though also across the river, lies further inland. Beyond describing the phonology, morphology, syntax, and usage of these underdocumented rural varieties, the grammar compares them with urban Jambi Malay, highlighting variation, contact, and sociolinguistic dynamics in the region. It contributes to a deeper understanding of dialectal diversity and historical continuity among Malay-speaking communities in central Sumatra.