Abstract : To conclude, I think that the Authors have been pioneers in bringing out the manuscript of the Oldest Grammar of Hindustānī written in 1698 by J. J. Ketelaar. The Authors have been successful in carefully analyzing and providing a clear commentary on the manuscript. Although Ketelaar’s grammar is not exactly what we have come to know as a grammar of language in modern days―be that descriptive or prescriptive―it nonetheless provides Hindi scholars with an important source of information, both linguistic as well as pedagogical, and opens up new directions in the history of the Hindi grammatical tradition.