Predicate-Argument Structure

256 Toni Badia, Carme Colominas
6.1.3 THE MODIFIERS
All major categories can have adjuncts, whether they can have subcategorised complements or
not. The abstract representation that we are aiming at should integrate the treatment of adjuncts
in a way which is as general and coherent as possible.
There are two basic classes of adjuncts: those that modify predicative elements and those that
modify non predicative (i.e., nominal elements). This is an important distinction, since the problems
that are encountered when dealing with them are not the same. In HPSG there is now a
reasonably established treatment for adjuncts to nominal signs, but there are not definite proposals
for adjuncts to predicative signs yet. This means that the determination of a particular
representation for adjuncts to predicative signs is one of the aims of this section.
Adjuncts to predicates can be further subdivided in those that can be interpreted in a restricted
way (in a way which resembles most of the adjuncts to nominals) and those that cannot. Examples
of the former class are locatives (whether temporal or spatial). Among the latter there are the
adjuncts that can be interpreted as semantic operators (causatives...), and also those that are wholly
external to the sentence (the constituents that do not clearly depend on the head).
An important aspect to be taken into account is that in many cases modifiers have the same form
(and very similar meaning) than subcategorised complements. This of course has to be taken into
account in order to produce results that are consistent with the treatment of complements. This is
important with respect to, for example, adjectives and PPs. Many adjectives can either be predicates
in copular constructions or noun modifiers, without any major change in meaning; consequently
the treatment proposed should explain these similarities and try to produce related lexical entries
for both cases. Similarly, there are PPs that can either be subcategorised for complements or
adjuncts to a predicative sign; also in this case there is no substantial change in meaning from one
another; the treatment of such adjuncts therefore should be compatible to that of the complements.
6.1.4 FORMAL ISSUES
From a formal point of view the aim of this section is to provide specifications for the design
of the content part of the sign. This is going to take the form of a “lean” HPSG, since as
described above (6.1.2), we are more interested in the coverage of our descriptions than in their
theoretical adequacy. In fact our proposal consists in a fairly detailed description of how the
different predicate-argument structures (and the modifiers) can be represented in a consistent,
levelled way. In some cases this is going to provide specifications which are clearly behind what
has been already obtained in the HPSG literature (like in the case of some adjuncts to predicative
signs, as in the proposal by Kasper (1994a), where a more semantically oriented proposal is made
for some of these modifiers), but in some others our proposal is going to treat phenomena that are
not covered by current HPSG literature (like in the case of the arguments to predicative nouns or
many complement types treated in the section on the lexical representation of verbs). To this end,
we propose in section 6.3 a type system which covers all of the cases treated; it basically follows
Pollard & Sag (1994) typing, but it obviously deviates from it in some ways to permit the specific
proposals contained in this section.
It is also important to bear in mind that the specifications provided are to be considered as
the input to parsing. In the exemplification performed in the final sections of this chapter, the
predicate-argument structures (and the modification relations) are represented in lexical entries of