This book gives a comprehensive introduction to Comparative Indo-European Linguistics. It starts with a presentation of the languages of the family (from English and the other Germanic languages, the Celtic and Slavic languages, Latin, Greek and Sanskrit through Armenian and Albanian) and a discussion of the culture and origin of the Indo-Europeans, the speakers of the Indo-European proto-language. The reader is introduced into the nature of language change and the methods of reconstruction of older language stages, with many examples (from the Indo-European languages). A full description is given of the sound changes, which makes it possible to follow the origin of the different Indo-European languages step by step. This is followed by a discussion of the development of all the morphological categories of Proto-Indo-European.