This paper investigates the structure of progressives and nominalizations in Chuj, an understudied Mayan language of Guatemala. Like many other Mayan languages, Chuj shows aspect-based split ergativity: the otherwise ergative head-marking pattern in the language disappears in the progressive aspect. In other Mayan languages—for example Ch’ol (Coon 2010; 2013) and Yucatec (Bricker 1981)—the appearance of a non-ergative pattern in the progressive has been attributed to nominalization. In Chuj, however, there is no clear morphological reflex of nominalization, as is found in other languages in the family. Using data from negation, particle placement, and agreement, we argue that Chuj progressives nonetheless involve an aspectual matrix predicate and a nominalized embedded verb. This provides a clear structural explanation for the split pattern. Finally, we distinguish different types of nominalizations in Chuj: those which are nominalized directly from a root, and those which are nominalized above verbal projections.