11. Rethinking the Clitic Doubling parameter: The inverse correlation between clitic doubling and participle agreement

This study focuses on the parameters that regulate the cross-linguistic distribution of clitic doubling and attempts to derive the availability of object clitic doubling on the basis of the systematic link between clitic doubling and participle agreement. The claim to be defended is that the presence of participial agreement determines the availability of clitic doubling: Participle Agreement excludes Clitic Doubling and vice versa (language internally as well as construction-specifically). The analysis relies crucially on the checking relations of phi-features that hold in clitic-languages. We argue that the presence of participle agreement in clitic-languages induces split-checking, which forces associates of the clitic to be null (pro). When no split-checking is required, a language may optionally be a clitic doubling language. The theory that emerges allows us to account for the clitic omission stage that occurs in child language. L1 learners undergo a stage (up to the age of 3) in which they are unable to establish split-checking relations between an XP and the functional heads involved. As a result, in languages in which such operations are required, clitic omission will arise.