According to the "Laryngeal Theory," Indo-European language --the putative ancestor of Celtic, Germanic, Balto-Slavic, Greek, Armenian, Indo-Iranian, and many other languages--possessed certain consonants called "laryngeals." Although one or two of these consonants live on in Anatolian Indo-European languages, "laryngeals" survive only as vestiges in the non-Anatolian Indo-European language family. This manual guides readers through the complexities of the "Laryngeal Theory," offering a clear and consistent introduction to an important aspect of Indo-European language studies. Casting new light on the phonologic system of Early Indo-European, the book will be welcomed by specialists as well as scholars and students of general linguistic theory.