The matrix: Merge and the typology of syntactic categories

In recent works (Moro 2000; 2009; Chomsky 2013; 2017; Chomsky et al. 2019; Rizzi
2015; 2016) a new type of phrasal structure has been assumed resulting from
Merging two XPs where neither XP projects: the unlabelled [XP YP]. This structure
stands out as an exception with respect to the typical X0 s and XPs. I will show
that by considering some basic properties of Merge in an abstract combinatorial
framework the stipulative character of this category is absorbed along with some
potential redundancies of UG.