Three marked theme constructions in spoken English

In this article we draw a distinction between two domains of discourse functions: discourse management functions and discourse content functions. We focus on three marked theme (topic) constructions: Extraposition (XP) (aka. Left Dislocation/Detachment), Object Fronting (OF) (aka. Topicalization, Y-Movement), and Subject Marking (SM). We provide empirical evidence from naturally occurring spoken English texts showing that all three constructions have discourse content functions, and that XP and SM also have discourse management functions. The discourse content functions demonstrated are contrast, similarity, enumeration, listing within the theme, and hedged disagreement. In addition, we found that in the domain of discourse management, XP signals an assertive opening move through which speakers mark the beginning of a new segment of talk around a certain discourse topic, whereas SM signals a sustaining move, through which speakers continue negotiating a given discourse topic despite some informational difficulty (e.g. heavy or new theme).