Bengali is spoken by over 48 millions of people, and naturally it has many dialects. These dialects range themselves into four main groups—Western, North Central, Northern, and Eastern (with a South-Eastern sub-group). The morphological differences between the four groups of dialects are slight, except in the case of the South-Eastern sub-group; but considerable divergences exist in sounds and phonology. These divergences, however, are not so great as to create mutual unintelligibility among speakers of Bengali in different parts of the country, except, perhaps, in the extreme east and south-east. The language which is commonly used in literature is a ‘high’ dialect, which is composite in its inflections, although it is based mainly on West Bengali of several centuries ago. The grammar of this ‘high’ Bengali—the sādhu bhāṣā, as it is called—is archaic, and explains most of the forms of the modern dialects as presenting the prototypes of these latter; but its pronunciation and intonation vary with the different dialectal areas.