Nahuatl, a Uto-Aztecan language dominant in Mesoamerica at the time of the Spanish Conquest. Spoken by the Nahuas of central Mexico, it became something of a lingua franca as their economic and political influence spread, especially during the time of the empire of the Triple Alliance. The Nahuas developed a tradition of secular and sacred record keeping in a partly pictographic, partly phonetic form in "paper books."
While overly zealous Spanish clergy destroyed most pre-Hispanic records after 1521, to facilitate Christian conversion some of them learned Nahuatl (and about Nahua culture) and taught indigenous people to write their language in European script. The Florentine Codex, a massive compilation of Mexica culture and history by indigenous informants under the direction of the Franciscan friar Bernardino de Sahagún, is a landmark of this process. Sahagún and other clergy produced Nahuatl-language confessional guides, sermons, grammars, and dictionaries. Indigenous writers preserved Nahuatl poetry and drama, and composed significant annals and histories in the native tradition.
But as important as such major works are, workaday Nahuatl records provide an even more intimate portrait of colonial indigenous society. By the later sixteenth century, community-based Indian notaries were producing thousands of testaments, petitions, land records, and the like that were recognized by the Spanish as legal documentation. Such documents are not important to modern scholars solely for their contents, though such information is often unobtainable elsewhere. Just as crucial is their linguistic evolution, marked by three major stages linked to the process of Hispanicization. As identified by linguist Frances Karttunen and historian James Lockhart, the first stage, coincident with the initial post-Conquest generation, involved the adoption of a few Spanish nouns and Nahuatl adapted to describe foreign objects. The second stage, lasting to the mid-seventeenth century and reflecting closer contact with Spaniards, was characterized by freer borrowing of Spanish nouns. In the third stage, continuing today and linked to increased culture sharing and growing bilinguality, verbs, participles, and the translation of Spanish idioms, as well as even more nouns, entered Nahuatl.
After independence, Nahuatl persisted as a principal language of the indigenous people, especially those living away from concentrations of Spanish speakers: during the Mexican Revolution, Emiliano Zapata had announcements translated into Nahuatl to accommodate the large number of monolingual Morelos citizens. In the twenty-first century Nahuatl is still spoken, though the continuation of third-stage borrowing would make it unintelligible to a sixteenth-century Nahua.
Nahuatl is now receiving a good deal of attention from scholars in several disciplines. An important study of the language is Frances Karttunen and James Lockhart, Nahuatl in the Middle Years: Language Contact Phenomena in Texts of the Colonial Period (1976). James Lockhart, The Nahuas After the Conquest: A Social and Cultural History of the Indians of Central Mexico, Sixteenth Through Eighteenth Centuries (1992), discusses the nature of the language, its evolution during the Spanish era, as well as the sociocultural implications of this evolution. A number of collections of English translations of Nahuatl documents with accompanying commentaries are available, including Arthur J. O. Anderson, Frances Berdan, and James Lockhart, Beyond the Codices: The Nahua View of Colonial Mexico (1976); S. L. Cline and Miguel León-Portilla, trans. and eds., The Testaments of Culhuacán (1984); James Lockhart, Arthur J. O. Anderson, and Frances Berdan, The Tlaxcalan Actas: A Compendium of the Records of the Cabildo of Tlaxcala (1545–1627), (1986); Frances Karttunen and James Lockhart, trans. and eds., The Art of Nahuatl Speech: The Bancroft Dialogues, (1987). Significant ethnohistorical studies that have relied heavily on Nahuatl documentation include S. L. Cline, Colonial Culhuacán, 1580–1600: A Social History of an Aztec Town (1986); Louise M. Burkhart, The Slippery Earth: Nahua-Christian Moral Dialogue in Sixteenth-Century Mexico (1989); Robert Haskett, Indigenous Rulers: An Ethnohistory of Town Government in Colonial Cuernavaca (1991). Among the most important colonial-era resources are the great dictionary of Alonso De Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana 2d ed., estudio preliminar de Miguel León-Portilla (1977); Andrés De Olmos, Arte para aprender la lengua mexicana, (1972); and Horacio Carochi, Arte de la lengua mexicana (1645).
Andrews, J. Richard. Introduction to Classical Nahuatl. Rev. ed. Norman: University of Oklahoma Press, 2003.
Carochi, Horacio. Grammar of the Mexican Language: With an Explanation of Its Adverbs (1645). Ed. James Lockhart. UCLA Latin American Studies, v. 89. Stanford, CA: Stanford University Press, 2001.
Chimalpahin Cuauhtlehuanitzin, Domingo Francisco de San Antón Muñón, Arthur J. O. Anderson, Susan Schroeder, and Wayne Ruwet. Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Texcoco, Culhuacan, and Other Nahua Altepetl in Central Mexico: The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin. 2 v. Norman: University of Oklahoma Press, 1997.
Flores Farfán, José Antonio. Cuatreros somos y toindioma hablamos: Contactos y conflictos entre el náhuatl y el español en el sur de México. Tlalpán, D.F.: CIESAS, 1999.
García Escamilla, Enrique. Neologismos nahuas: Incorporación de voces de la vida actual al vocabulario de la lengua azteca. México, D.F.: Plaza y Valdés Editores, 1999.
Hernández Sacristán, Carlos. Introducción a la lengua y cultura nahuas. València: Universitat de València, Departament de Teoria dels Llenguatges: Instituto Valenciano de Lenguas y Culturas Amerindias, 1997.
Lockhart, James. Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts. Stanford: Stanford University Press, 2001.
Ruiz González, Francisco Javier. Nahuatlismos en el español de México. Zapopan: SIMA Editores, 2001.
Siméon, Rémi. Diccionario de la lengua nahuatl o mexicana. Trad. Josefina Oliva de Coll. México: Siglo Veintiuno,  1999.
Na·hua·tl / ˈnäˌwätl/ • n. (pl. same) 1. a member of a group of peoples native to southern Mexico and Central America, including the Aztecs. 2. the Uto-Aztecan language of these peoples. • adj. of or relating to these peoples or their language.