Complementizer doubling and subject extraction in Italo-Romance

In this article I analyze the complementizer doubling construction attested in some early and modern Italo-Romance varieties, where a preposed (clausal or non clausal) constituent associated to the selected clause appears in the embedded left periphery preceded and followed by a subordinating complementizer. While the higher complementizer is uncontroversially interpreted as a lexicalization of the head Force°, the lower one has been taken to lexicallize either the functional head Topic° or the functional head Fin°. Relying on previous formal analyses of subject extraction, I argue that in the varieties in which the lower complementizer lexicalizes Fin°, its presence reflects the lexicalization of the mood features encoded by Fin°, and is ultimately due to the extraction of the thematic subject out of the embedded clause through Spec,FinP, a movement strategy made possible by the presence of an expletive pro in the canonical preverbal subject position