@PIE

According to Western grammarians, Sanskrit evolved gradually from PIE, that is, Proto-Indo-European, an unattested language, from which most European languages also evolved.

qq(see wikipedia on Proto-Indo-European_language).

Acording to Indian popular belief, however, Sanskrit was already perfect when the world was created, and all other languages are corruptions of Sanskrit that arose when kaliyuga कलियुग set in and people were no longer smart enough to talk correctly without studying.