This dissertation is a grammatical description of several features of the morphology and phonology of the Mocho' language. Mocho' (Motozintleco) is a moribund Mayan language spoken in the Chiapas region of Mexico near the border of Guatemala. This dissertation, based on data collected during several field trips and supplemented with unpublished data from previous researchers, provides an overview of the grammatical structure of Mocho'. The topics covered include phonology, loanwords, root structure, derivation and inflection of the different word classes, important discourse particles, and unique features of the Mocho' language. Mocho' is one of only four Mayan languages to develop a tonal contrast; the Mocho' pattern is unique and has developed recently. Mocho' has several grammatical features which are unique in Mayan, including the development of middle voice from Proto-Mayan antipassive marking and the patterning of positionals, negatives, and syntactic markers of direction, location, and motion. Mocho' has a split ergative system, with ergative marking on third persons and nominative-accusative marking on first and second persons. Mocho' also has unique patterns of definiteness and evidentiality. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]