The present book which is based on comprehensive research work made by the author in the domain of Code-Switching also seeks to investigate some of such problems arising out of code-switching. More specifically it covers the sociolinguistics of code-switching in Urdu-English. Most of the data that have been used for the purpose of investigation are from Delhi the capital city of India as the city is a home to a variety of speech community Lucknow and Hyderabad become the centres of Urdu literature in the 19th century.