Indo-Aryan peoples
Vedic Sanskrit has a number of linguistic features which are alien to most other Indo-European languages. Prominent examples include: phonologically, the introduction of retroflexes, which alternate with dentals, and morphologically, the formation of gerunds. Some philologists attribute such features, as well as the presence of non-Indo-European vocabulary, to a local substratum of languages encountered by Indo-Aryan peoples in Central Asia and within the Indian subcontinent, including the Dravidian languages.