Purpose: This review introduces emergentism, which is a leading theory of language development that states that language ability is the product of interactions between the child's language environment and his or her learning capabilities. The review suggests ways in which emergentism provides a theoretical rationale for interventions that are designed to address developmental language delays in young children. Method: A review of selected literature on emergentist theory and research is presented, with a focus on the acquisition of early morphology and syntax. A significant method for developing and testing emergentist theory, connectionist modeling, is described. Key themes from both connectionist and behavioral studies are summarized and applied with specific examples to language intervention techniques. A case study is presented to integrate elements of emergentism with language intervention. Conclusions: Evaluating the theoretical foundation for language interventions is an important step in evidence-based practice. This article introduces three themes in the emergentist literature that have implications for language intervention: (a) sufficiency of language input, (b) active engagement of the child with the input, and (c) factors that increase the odds for correctly mapping language form to meaning. Evidence supporting the importance of these factors in effective language intervention is presented, along with limitations in that evidence.