The articles presented in this study represent four of the seven Nahuatl dialects in which the Summer Institute of Linguistics workers are currently involved. Tentative conclusions from the dialect testing teams engaged in measuring degree of intelligibility between Nahuatl dialects suggest that almost a dozen mutually unintelligible Nahuatl areas of speech must be dealt with separately and seriously. In addition to defining dialects for the purpose of preparing literacy materials and Bible translation for indigenous peoples, publishing sets of articles on related dialects of one language family provides the raw materials for a pan-Nahuatl grammar based on "competence," not simply on "performance." Contents are: "Isthmus Veracruz (Mecayapan) Nahuat Laryngeals," by C. Wolgemuth;"Puebla (Sierra) Nahuat Prosodies," by D. F. Robinson; "Morelos (Tetelcingo) Nahuatl Verb Stem Constructions," by F. Brewer; and "Michoacan (Pomaro) Nahual Clause Structure," by D. F. Robinson and W. R. Sischo. (AMM)