Edwin W. Fay, a professor of comparative linguistics at the University of Texas who was known for his translations of the Rig-veda Mantras In The Grhya Sutras, gives a clear overview and analysis of agglutination and adaptation in Indo-European languages. His central premise is to complicate the idea of phonetic law – that is, the idea that sounds will follow specific patterns of change within a particular language. He uses the process of agglutination (the addition of suffixes to a word root) and adaptation (changing a foreign word to fit the grammar of a different language) to explain the base patterns of a variety of languages and also to account for the “exceptions” to the “law” of phonetics. A good read for linguists, particularly those with interests in ancient language.