Auxiliary + Predicative Phrase

In GPSG ([#!gazdar85!#], [#!sag85!#]) the copula is treated as an auxiliary verb that takes an X² category with a + value for the head feature [PRD] (predicative). AP, NP, PP and VP can all be [+PRD], but a Feature Co-occurrence Restriction guarantees that a [+PRD] VP will be headed by a verb that is either passive or a present participle. GPSG follows [#!chomsky70!#] in adopting the binary valued features [V] and [N] for decomposing the verb, noun, adjective and preposition categories. In that analysis, verbs are [+V,-N], nouns are [-V,+N], adjectives [+V,+N] and prepositions [-V,-N]. NP and AP predicative complements generally pattern together; a fact that can be stated economically using this category decomposition. In neither [#!sag85!#] nor [#!chomsky70!#] is there any discussion of how to handle the complete range of complements to a verb like seem, which takes AP, NP and PP complements, as well as infinitives. The solution would appear to be to associate the verb with two sets of rules for small clauses, leaving aside the use of the verb with an expletive subject and sentential complement.