Sequentiality in dialogue as a trigger for grammaticalization
Using the rise of three final particles in spoken English (<i>then</i>, <i>though, anyway</i>) as a case study it will be shown that dialogic interaction is an important domain of grammaticalization. The central idea is that grammaticalization may be induced by the regularization of interactive sequences which, over time, freeze into dialogic schemas and trigger a change of originally lexical or sentence-internal grammatical items involved in such schemas into elements establishing relations beyond the sentence level. The study shows that the proper domain of grammaticalization is not an individual element, but the dialogic context in which it is regularly used. Corpus-based, empirical data are used to document the grammaticalization of the three final particles in different text types within a framework that conceives of grammaticalization as structural and contextual expansion (rather than reduction) and as a functional (rather than formal) change.