The status of complementizers in the left periphery

In Section 1 we argue that the nominal nature of complementizers in many languages (notably wh-items in Romance) points to the conclusion that this extra embedding layer is nominal (cf. Rosenbaum 1967). In Section 2 we address the question whether the structures they create are more similar to headed relatives (Arsenijević 2009; Kayne 2010, to appear) or to free relatives (Manzini & Savoia 2003, 2005, 2011). In Section 3 we consider some of the empirical reasons that would recommend distinguishing between complementizers and wh-items, including selection, islands and order in the left periphery. We also consider finiteness restrictions (Section 4). In Section 5 we conclude by indicating what this line of research implies for Main Clause Phenomena.