The Cartography of Negative Markers: why negation breaks the assumption of LF/PF isomorphism

In a recent review of the cartographic approach to syntactic structures, Cinque & Rizzi (2010) suggested the possibility that functional hierarchies might be the reflex of semantic principles of compositionality which have been grammaticalized. This view carries the implicit assumption that the relation between LF and PF is isomorphic, at last for what concerns clausal operators. However, this assumption seems to be untenable once extended to clausal negation, where cross-linguistic variation in the IP field (Zanuttini 1997, Ouhalla 1990, Miestamo 2003) and in the Left Periphery (Moscati 2010a) does not translate in an analogous LF variation.