The approach to grammar developed by Leonard Talmy. Like other cognitive approaches to grammar Talmy assumes the symbolic thesis and thus treats grammatical units as being inherently meaningful. However, Talmy's model is distinguished by its emphasis on the qualitative distinction between closed class forms (grammatical subsystem) and open class forms (lexical subsystem). Talmy argues that these two forms of linguistic expression represent two distinct conceptual subsystems which encode qualitatively distinct aspects of the human conceptual system. These are the conceptual structuring system and the conceptual content system. While closed class forms encode schematic meaning and constitute the conceptual structuring system, open class elements encode meanings that are far richer in terms of content, content meaning, and thus constitute the conceptual content system. In his research, Talmy is primarily interested in delineating the nature and organisation of the conceptual structuring system. In particular, Talmy is concerned with establishing the nature and function of the conceptual structuring system as encoded by closed class elements.

For Talmy this issue is a particularly fascinating one as in principle, language could function with a lexical or conceptual content system alone. The fact that languages do not makes establishing the distinction in terms of the respective contributions of the two subsystems in encoding and externalising our cognitive representation a particularly intriguing one.