Linguists are careful not to call Bozo one language. It is a dialect cluster with real internal diversity, and the reference catalog Ethnologue splits it into four languages, a division driven partly by the practical question of which communities need their own literacy materials. The varieties carry names that sing in the original orthography: Hainyaxo, Tieyaxo, Tiema Cewe, and the large central group Sorogaama, also called Jenaama. That last one alone claimed around 200,000 speakers in 2005 and breaks down further into its own dialects, including Pondori south of Mopti, Korondugu to the north, and Debo, named for the lake at the delta's heart.

The dialects are a map of the river. Hainyaxo, spoken by the people who call themselves the Hain, sits at the western edge, holding two pockets along the Niger. Its eastern neighbor Tieyaxo is spoken around Diafarabe, the town famous for the cattle crossing where Fulani herders drive their animals back across the river each year. The widely spoken Jenaama group spreads through the delta's core around Mopti and Lake Debo, while Tiema Cewe clings to the northeastern fringe near the lake. To trace the dialect boundaries is to trace the channels, lakes, and seasonal floods of one of Africa's great inland waterways.

Bozo belongs to the northwestern branch of the Mande languages, and its closest relative is Soninke, the tongue of the merchant communities scattered across southern Mali, eastern Senegal, and southern Mauritania. That kinship hints at deep history in the western Sudan, where Mande peoples built kingdoms and trade networks for centuries. The Bozo themselves rarely speak only their own language; most also command one or more of the regional tongues, Bambara, Fula, or Western Songhay, the practical multilingualism of people whose livelihood depends on dealing with everyone the river brings. The fishing follows the Bozo beyond Mali too, into Nigeria, Burkina Faso, and Ivory Coast, where the Jenaama dialect is known by another name entirely, Sorko.