Patois is a creole language whose vocabulary largely comes from English, and there’s a gradient of dialects between Patois and Jamaican Standard English, but pure Patois is considered mutually unintelligible with Jamaican English and thus a separate language. Moreover:

A 2007 survey by the Jamaican Language Unit found that 17.1 percent of the population were monolingual in Jamaican Standard English (JSE), 36.5 percent were monolingual in Patois, and 46.4 percent were bilingual, although earlier surveys had pointed to a greater degree of bilingualism (up to 90 percent).