The interaction of components in a functional discourse grammar account of grammaticalization

The main goal of this paper is to show how the usage-based nature and pragmatic motivations of grammaticalization can be felicitously accommodated within the framework of Functional Discourse Grammar (Hengeveld and Mackenzie 2008), a typologically-based theory of language structure that conceives the grammar as one component of a wider model of verbal communication, constantly interacting with a Conceptual and a Contextual Component. Starting from the idea that grammatical meaning diachronically results from the gradual conventionalization of an invited inference (Traugott and Dasher 2002; Heine 2002), the paper suggests that the successive stages into which this process can be broken down differ from each other as to the role played by each component in the selection and interpretation of the grammaticalizing construction. Taken together with Functional Discourse Grammar's capacity to formulate separate clines of grammaticalization for each grammatical level (pragmatics, semantics, morphosyntax, phonology), the proposed model offers a systematic and formalized account of the entire grammaticalization process: from the synchronic inferential mechanisms that trigger it to the ultimate outcomes of the functional and formal evolution of the grammaticalized item. The workings of the model are illustrated through the analysis of concrete cases of grammaticalization, with special focus on TAM markers.