Greek phrasal and reduced clausal comparatives diff er in that the former, but not the latter, show island sensitivities. In neither case, however, is the material that constitutes the island pronounced. Th is paper argues that such facts can only be captured by positing abstract unpronounced syntactic structures; the comparison between the two kinds of comparatives further shows that reducing the island eff ects to semantic or other ill-formedness is not possible: the island eff ects are irreducibly syntactic. Such facts provide support for syntactic architectures that countenance this kind of abstractness, and against surfacist syntactic theories.