This, the Second Edition of The Navajo Language: A Grammar And Colloquial Dictionary, includes a wide range of additional linguistic information, developed since the appearance of the First Edition, in 1980. The entire grammatical section has been revised and rewritten, in expanded form, and additions to the appendix now include an article on Comparative Athapaskan along with a Navajo / Pre-Proto- and Proto-Athapaskan root inventory, based on comparative linguistic data prepared by linguists at the Alaska Native Language Center, University of Alaska; a stem index cross-referenced to the root inventory; a separate Navajo noun inventory, arranged by type; and an exhaustive set of model paradigms to which the verb prefix inventory, in the main body of the grammatical section is cross-referenced.