Romance pronominal clitics as pure heads

Romance clitics are currently accounted for as DP arguments moved to functional head positions or as functional heads (AccVoice, etc.) licensing pro-DPs in argument position. I take the view that clitics are first merged as heads, projecting independently motivated categories on the functional spine of the sentence (φP, ApplP). I argue that they can satisfy theta relations without need for a pro associate. From an empirical point of view, a pure head syntax for clitics is favoured in explaining the asymmetries between clitics and phrases, found in several syntactically relevant domains (order, agreement, case). I show how the hypothesis that clitics are functional heads derives the internal order of the clitic string, which does not necessarily match (or mirror) that of phrasal constituents. I also consider agreement asymmetries (perfect participle agreement) and case asymmetries (in relation to Differential Object Marking).