In this companion volume to History and Mythology of the Aztecs, John Bierhorst provides specialists with a transcription of the Nahuatl text, keyed to the translation, and a linguistic apparatus to help elucidate it. The Glossary offers definitions for all unusual usages in the codex, as well as careful treatment of many of the commonest (and most semantically flexible) verbs, adverbs, and particles. Detailed discussions of selected features appears in the Grammatical Notes, which complete the work.
John Bierhorst is the author, editor, or translator of more than thirty books on Native American lore, including Latin American Folktales, The Mythology of South America, The Mythology of North America, and The Mythology of Mexico and Central America.
I have actually just skimmed this book, since after a very few words into the actual codex itself, it became clear that I needed a companion volume (also by Bierhorst) to do my own translation. I'm fascinated by Nahuatl, being one of the relatively few native American languages that is not only surviving but thriving. As soon as I am able to make more headway on the translation, I will re-visit this review.