This chapter overviews scholarship in functional linguistics, and focuses on constituency, a specific problem which has attracted significant attention from functionalists. It examines constituency from the perspective of a natural outgrowth of functionalism in linguistics, namely a concern with the function of grammar in its ecological habitat, conversational interaction. Functional approaches to patterning in language, then, have recently shifted the focus away from synchrony to diachrony and grammaticization. The chapter explores the role of constituent schemas in allowing conversational interactants to produce and monitor turns at talk for their trajectories and what it might take for them to be finished. It discusses three ways in which constituency works to help speakers manage interactional tasks. The operations of projection, expansion, and retraction are first and foremost interactional tasks, for which constituent schemas afford a solution.

Broca's area has long been implicated in articulatory-related speech production and for good reason. Although there has been much discussion of the role of Broca's area in syntactic computation, especially during comprehension, there is little evidence supporting the claim for any linguistic-specific computation performed in Broca's region. It has been suggested that Broca's area supports some aspects of sentence processing via a more general role in cognitive control, which includes mechanisms involved in resolving conflicts between competing representations or conflicting information. The necessity for conflict resolution arises in a range of language processing situations where ambiguity exists including phonological, lexical, and sentential contexts. The discovery of mirror neurons in the macaque frontal cortex has sparked renewed interest in the role of the motor system in the perception of speech sounds, an idea that is clearly related to the motor theory of speech perception.