Labeling and two types of null operators in English

This paper investigates null operator (Op) movement in English clausal comparatives, temporal clauses and tough constructions. It claims that the difference among them, which concerns the clause-boundedness of Op movement in tough constructions, can be explained by assuming that a Complex Null operator (CNO) is involved in such constructions based on Hicks’s (2009) smuggling approach while the null operators in other environments (comparatives, temporal clauses) are the simple head Ops. The Activation Condition (Chomsky 2000) and the Labeling Algorithm (Chomsky 2013) are appealed to in implementing feature-checking between the CNO and CP, which has a freezing effect on the operator in the embedded clause (Rizzi 2006, 2007). It is also argued that the simple Op keeps moving to project itself in the complement positions of certain prepositions which can assign Inherent Case through the head-complement relation.