A new theory of the syntax-semantics interface that relies on hierarchical orderings in language, with the English auxiliary system as its empirical ground.Research in syntax has found that there is a hierarchical ordering of projections within the verb phrase across languages (although researchers differ with respect to how fine grained they assume the hierarchy to be). In Situations and Syntactic Structures, Gillian Ramchand explores the hierarchy of the verb phrase from a semantic perspective, attempting to derive it from semantically sorted zones in the compositional semantics. The empirical ground is the auxiliary ordering found in the grammar of English. The "situation" in the title refers to the semanticists' notion of eventuality that is the central element of the ontology of the formal semantics of verbal meaning. Ramchand discusses the semantic notion of situations in relation to the hierarchical ordering evidenced in syntactic structures and tries to bridge semantic and syntactic ontologies. She proposes and formalizes a new theory of semantic zones, and presents an explicitly semantic and morphological analysis of all the auxiliary constructions of English that derive their rigid order of composition without recourse to lexical item-specific ordering statements.