Charles Ferguson (1959),in the article Diglossia, brought into focus the phenomenon of diglossia as the functional coexistence of two linguistic varieties,each with its own contexts for use. This kind of intimate dual existence is different from bilingualism or functional variation between standards and dialects. Bengali is spoken by over 70 million people in India alone. This study was conducted in Kolkata, the capital of West Bengal,India. Kolkata has been a trendsetter of language from its very birth during the time of British rule in India, in the late seventeenth century. It was here that sadhu (the prestigious variety), colit (the newly created everyday variety), and sadhu-colit (an intermediate variety) took shape. The results reveal the dynamics of a fluid linguistic situation where sadhu has become restricted to a few formal domains; whereas colit, has gained in popularity; and sadhu-colit is not a viable alternative. In addition, English has gained ground. The study predicts that colit will prevail as the dominant variety of Bengali,while sadhu becomes purely symbolic and English expands to cover areas of the modern world.