Functional Discourse Grammar
Functional Discourse Grammar (FDG) is the most recent edition of Functional Grammar (FG). Its main developers are Kees Hengeveld and J. Lachlan Mackenzie, but members of the Amsterdam-based Functional Grammar Colloquium were actively involved from its inception. Being more suitable for the analysis of phenomena that exceed the level of the clause than its predecessor, while retaining most of its merits, Functional Discourse Grammar has gradually come to replace the use of Functional Grammar, although the two coexist quite happily.
With regard to the model's architecture, the most important change in comparison with FG is that the underlying representation has now been divided over four hierarchically ordered levels of analysis, each of which deals with a single analytical domain (discourse pragmatics, semantics, morphosyntax and phonology). The underlying representations at these levels obey the same algorhitm that was already in place in FG.
Furthermore, Grammar in FDG has been embedded in a wider model of cognitive modules that assist in verbal interaction (the Conceptual and Contextual components, as well as an interface with the articulatory and auditory systems). Although FDG remains agnostic as to the internal structure of these modules, this architectural reconception draws particular attention to the interaction between Grammar and surrounding systems.