The Linguistic Survey of India (LSI) is an ongoing project of the Government of India that aims to document and study how languages have changed in the country over the years. It considers shifts in society, administrative regions and the reorganisation of states based on linguistic identity. This project has been undertaken by the Language Division, Office of the Registrar General, Government of India. Part of this project is the ‘Linguistic Survey of India–Bihar’ which studies the seven languages spoken in Bihar. The surveys were carried out between 1980 and 2000, spanning the time before the state of Jharkhand was carved out of Bihar on November 15, 2000. The survey works on the census framework according to which ‘language’ and ‘mother tongue’ are ‘co-terminus’ or mean the same. The volume lists Hindi, Maithili, Urdu as the official languages of the state while Bhojpuri, Kurmali Thar, Magahi, Surjapuri are the mother tongues. This selection of the languages is based on regional importance, the number of speakers, and the locations where the survey was conducted in undivided Bihar. The present-day LSI is an extension of the survey first proposed by George Abraham Grierson, an Irish linguist who documented Indian languages during the pre-Independence era and a few years of the early 20th century. This survey “complements and supplements” Grierson's survey conducted when the states of West Bengal, Bihar, Jharkhand, Odisha, and present-day Bangladesh were part of the same province called the Bengal Presidency. The document is divided into nine main chapters. The first chapter introduces the history of the state, the demographics, and linguistic profile of the state vis-a-vis the population density, along with the status of bilingualism and trilingualism. The second, third and fourth chapters focus on the grammatical description of the three official languages while chapters five, six, seven and eight describe the four mother tongues spoken in Bihar...