This article outlines an account of the syntax of existential constructions (e.g., There are [too many problems]) based on a view of the postcopular NP as a predicate. This NP figures as the predicate in an embedded clausal complement of be with expletive there as its subject. There consequently moves to the higher Spec,IP position for Case-theoretic reasons. Existential constructions and existential interpretation are a particular instance of a wider phenomenon involving the use of predicates of various categories with expletive subjects (e.g., It is cold). Long-distance agreement between the main (inflected) verb and the postcopular NP is a combined effect of the relation of subject-predicate agreement holding between the expletive subject (there) and a predicate NP within the embedded clausal structure and the relation of specifier-head agreement (feature checking) between the raised expletive and the matrix I/T. This analysis is generalized to other cases of long-distance agreement (e.g., There appeared a man). It is shown that an analysis based on the notion Agree (Chomsky 2000) is empirically inadequate. Well-known restrictions on the distribution of NPs/ DPs in existential constructions follow from the proposed analysis.