Specifying who: On the structure, meaning, and use of specificational copular clauses

This dissertation is concerned with a class of copular clauses known as specificational clauses, and its relation to other kinds of copular structures, predicational and equative clauses in particular.; Based on evidence from Danish and English, I argue that specificational clauses involve the same core predication structure as predicational clauses---one which combines a referential and a predicative expression to form a minimal predicational unit---but differ from them in how the predicational core is realized syntactically. Predicational copular clauses represent the canonical realization, where the referential expression is aligned with the most prominent syntactic position, the subject position. Specificational clauses involve an unusual alignment of the predicative expression with subject position. Building on work by Prince (1992) and Birner (1996), I suggest that this unusual alignment is grounded in information structure, and, ultimately, principles of discourse coherence: the alignment of the less referential DP with the subject position serves a discourse connective function by letting material that is relatively familiar in the discourse appear before material that is relatively unfamiliar in the discourse.; I develop an analysis of predicational and specificational clauses that integrates these findings. The central syntactic mechanism that governs the derivation of the two kinds of clauses is the featural interaction between the two DPs and T, the host of the subject position. Part of this interaction is familiar from non-copular clauses, but characteristic properties of copular clauses, in particular the semantic asymmetry between the two nominals and the lightness of the copula verb itself, conspire to let information structure play a decisive role in determining which of the two DPs raises to subject position.; The analysis provides a basis for understanding the restrictions on the kinds of DPs that can occur as subjects of specificational clauses; only DPs that can denote properties and that allow the specificational clause to perform its connective discourse function can occur in this position. It further clarifies the relation between specificational and predicational clauses, and effectively sets them both apart from equative clauses, which are argued to be fundamentally different.