Board member, Navajo Language Academy. Related Publications The Navajo prolongative and lexical structure. In E. Jelinek (ed), Coyote Papers: Festschrift for Kenneth Hale. In press. The semantics of the Navajo verb base. 2000. In T. Fernald & P. Platero (eds), The Athabaskan Languages: Perspectives on a Native American Language Family. Dordrecht: Kluwer. Ch 12: The Aspectual System of Navajo, The Parameter of Aspect. Dordrecht: Kluwer. 2nd revised edition, 1997. Aspectual categories in Navajo. International Journal of American Linguistics, 62, 227-263. 1996. Review: Axelrod, Melissa. The Semantics of Time: Aspectual Categorization in Koyuko. Lincoln, Nebraska: University of Nebraska Press. American Anthropologist 1995.