High Quality Content by WIKIPEDIA articles! The numerals of the Proto-Indo-European language (PIE) have been reconstructed by modern linguists based on similarities found across all Indo-European languages. The following article lists and discusses their hypothesized forms.The Proto-Indo-European language (PIE) is the unattested, reconstructed common ancestor of the Indo-European languages, spoken by the Proto-Indo-Europeans. The existence of such a language has been accepted by linguists for over a century, and there have been many attempts at reconstruction. Nevertheless, many disagreements and uncertainties remain.