This is the first type of work in the history of Sanskrit linguistics. So far though a number of studies on the Grammatical and Linguistic aspects of Vedic as well as Classical Sanskrit have been carried out, but a contrastive study taking into account phonological and morphological features of Sanskrit language from the point of view of modern linguistics has remained a desideratum. The few efforts made in this direction are neither comprehensive not systematic in their treatment. Keeping in view of the necessity of such a study, this work has been undertaken. It has been produced in parts. First part deals with the phonological features and second part deals with morphological features. This study enables scholars and students to understand the historical evolution of Vedic language and origin and development of Classical Sanskrit. It also sheds new light on the linguistic problems of Indo-European, Middle Indo-Aryan and Modern Indian languages which have remained unexplained so far.