Construction-based analyses have been rejected by Chomsky and others because they have been judged incapable of expressing appropriate generalizations about grammar. This talk presents an overview of the theory of English clausal constructions sketched in Ginzburg and Sag (2000). Following the insights of Fillmore and Kay, constructions are taken to be basic units of grammar. Multiple-inheritance hierarchies provide the means for expressing cross-constructional generalizations of considerable subtlety.
An HPSG-style construction grammar is a recursive system of signs -- modelled as typed feature structures, where phrasal signs are partitioned into two dimensions: headedness and clausality. Each basic phrase type (a `leaf' in the phrase hierarchy) is classified in terms of both headedness (hd-subj-phrase, unheaded-phrase, etc.) and clausality (decl-clause, inter-clause, non-clause, etc). A grammar includes constraints applying at varying grains in the construction hierarchy which are inherited by instances of the leaf types, via well-understood techniques developed within the paradigm of object-oriented computing. Each basic type of construction is thus roughly equivalent to a phrase structure rule, all of whose categories are typed feature-structure complexes, e.g.
|decl-hd-subj-cl | |SUBJ <> | |SUBJ < > | --> |SYNSEM  | HD: |VFORM fin | | ... | | ... | | ... |
However, because of the hierarchical organization imposed on constructions, each such type inherits many of its properties from superordinate types, thus allowing a natural account of `family resemblances' across particular constructions, e.g. the `extraction' involved in topicalization, wh-interrogatives, wh-exclamatives, and wh-relatives.
I will present an overview of our account of basic declarative (indicative and subjunctive), interrogative (polar, WH, and in situ), and exclamative (inverted and WH) clauses. The diverse properties of individual constructions are accommodated through the interaction of constructional constraints of varying grain and a high-level default principle -- the Generalized Head Feature Principle, which ensures that, in the absence of particular constraints stating otherwise, a head daughter and its mother share all grammatical information.
Ginzburg, Jonathan and Ivan A. Sag. 2000. Interrogative Investigations: the form, meaning and use of English Interrogatives. Stanford: CSLI Publications. Distributed by University of Chicago Press.