Functional relations in the English auxiliary system

This article addresses the question of the syntactic functional relations between English auxiliaries and the verbal elements that follow them. There are two basic types of analysis: either the auxiliary is the head and the VP is the complement, or the "main verb" is the head and the auxiliary is a feature-bearing modifier. It is argued here that there is no single correct analysis for all English auxiliaries: some (do, have, will/shall, would) are feature-bearers while others are argument-taking predicates.