The proposed Proto-Indo-European language (PIE) is the reconstructed common ancestor of the Indo-European languages, spoken by the Proto-Indo-Europeans. From the 1960s, knowledge of Anatolian became certain enough to establish its relationship to PIE.
Over the course of many centuries, the Finnish language has borrowed many words from a wide variety of languages, most from neighbouring Indo-European languages. Owing to the different grammatical, phonological and phonotactic structure of the Finnish language, loanwords from Indo-European have been assimilated.