Sanskrit in their era was a language that is spoken () by the cultured and educated. Some sutras expound upon the variant forms of spoken Sanskrit versus written Sanskrit. The 7th-century Chinese Buddhist pilgrim Xuanzang mentioned in his memoir that official philosophical debates in India were held in Sanskrit, not in the vernacular language of that region. According to Sanskrit linguist professor Madhav Deshpande, Sanskrit was a spoken language in a colloquial form by the mid-1st millennium BCE which coexisted with a more formal, grammatically correct form of literary Sanskrit. This, states Deshpande, is true for modern languages where colloquial incorrect approximations and dialects of a language are spoken and understood, along with more "refined, sophisticated and grammatically accurate" forms of the same language being found in the literary works. The Indian tradition, states Winternitz (1996), has favored the learning and the usage of multiple languages from the ancient times. Sanskrit was a spoken language in the educated and the elite classes, but it was also a language that must have been understood in a wider circle of society because the widely popular folk epics and stories such as the Ramayana, the Mahabharata, the Bhagavata Purana, the Panchatantra and many other texts are all in the Sanskrit language. The Classical Sanskrit with its exacting grammar was thus the language of the Indian scholars and the educated classes, while others communicated with approximate or ungrammatical variants of it as well as other natural Indian languages. Sanskrit, as the learned language of Ancient India, thus existed alongside the vernacular Prakrits. Many Sanskrit dramas indicate that the language coexisted with the vernacular Prakrits. The cities of Varanasi, Paithan, Pune and Kanchipuram were centers of classical Sanskrit learning and public debates until the arrival of the colonial era. According to Lamotte (1976), an Indologist and Buddhism scholar, Sanskrit became the dominant literary and inscriptional language because of its precision in communication. It was, states Lamotte, an ideal instrument for presenting ideas, and as knowledge in Sanskrit multiplied, so did its spread and influence. Sanskrit was adopted voluntarily as a vehicle of high culture, arts, and profound ideas. Pollock disagrees with Lamotte, but concurs that Sanskrit's influence grew into what he terms a "Sanskrit Cosmopolis" over a region that included all of South Asia and much of southeast Asia. The Sanskrit language cosmopolis thrived beyond India between 300 and 1300 CE. Dravidian influence on Sanskrit