Relations between preschool-aged children’s expressive language ability and externalizing behaviors remain poorly understood and may be moderated by other influences, including child sex, temperamental anger/frustration, receptive language, and adaptive communication skill (i.e., “real-world” usage of language). The present study used person- and variable-centered approaches to (a) identify meaningful classes of children based on these attributes, and (b) test for class-specific differences in the relation between expressive language and later externalizing behaviors. Participants were 144 preschool-aged children (M = 47.43 months; 51% male) who were recruited from semirural Head Start centers and assessed at two time points, approximately five months apart. Latent class analysis identified three classes of children: (a) the Typical Language/Higher Anger class (average language/communication abilities and higher anger/frustration), (b) the High Communication/Average Anger class (only female children with high adaptive communication and otherwise average attributes), and (c) the Verbally Competent/Lower Anger class (high language/communication abilities and lower anger/frustration). Expressive language negatively predicted Time 2 externalizing behaviors more strongly among the High Communication/Average Anger class, compared to the Typical Language/Higher Anger class. Across the entire sample, there was a negative predictive relation between expressive language and Time 2 externalizing behaviors, which was moderated by anger/frustration and adaptive communication. Overall, among children with competent skills in expressive language and at least one additional domain (e.g., higher adaptive communication, lower anger/frustration), higher expressive language more strongly predicted lower levels of Time 2 externalizing behaviors, relative to children with fewer concurrent competencies. Higher levels of expressive language were not related—or were less strongly related—to later externalizing behaviors among children with fewer concurrent competencies. Results underscore the proximal role of temperamental and adaptive communicative attributes in supporting expressive language usage and suggest different intervention strategies for children with different configurations of attributes. / Psychology