The answer is, no one knows, or can ever know, given that these populations left no writings to be deciphered. read more
The only extant non Indo-European language native to Europe is the Basque language, euskara, of Northern Spain and South-Western France. Ancient Iberians spoke a non-Indo-European language, and this may or may not have been the same or related to Basque. read more
While Indo-European was mainly Bronze Age. It is a wonder to me if many dialects of Uralic were spoken in Europe during the Neolithic; a few centuries before Indo-European invasion. It would partially explain why many Uralic cultures have very unusual Y-DNA patterns. read more