Chittagonian, also known by its endonym Chatgaya is an Indo-Aryan language spoken in the Chittagong Division in Bangladesh. It is generally considered to be a nonstandard dialect of Bengali because its speakers identify with Bengali culture and Standard Bengali as literary language, but the two are not mutually intelligible. It is estimated (2009) that Chittagonian has 13–16 million speakers, principally in Bangladesh.
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