“Since Saussure, linguistic research has assumed that ‘langue’ and ‘parole’ must be kept separate. This view of language has been challenged by the usage-based approach, in which grammar and usage are inextricably connected. Language is a dynamic system of emergent symbolic units and flexible constraints that are shaped by general cognitive processes involved in language use. Foundational works include those of Joan Bybee and Ronald Langacker, and important others include Michael Tomasello.”