Preliminary Recommendations

A comparison

In all the approaches reviewed, subcategorisation involves an argument structure providing a specification of the participant structure of a predicate, and a linking specification which determines the functional/syntactic realisation of participant roles of the predicate.

In GB, LFG and DUG, argument structure is defined as a level of syntactic description; in HPSG and UCG, argument structure is part of the semantic representation of predicates. Thematic role annotations are used in GB, LFG and UCG to rank participants; this ranking determines the syntactic functionality of participants. In GB, the external/internal argument distinction is crucial in the determination of the structural realisation of participant roles. This distinction is not semantically motivated; it is simply assumed as a lexical specification. In LFG, a Universal Thematic Hierarchy is assumed. In the 1994 version of HPSG, there is no ranking of participant roles. In UCG,  ranking is semantically expressed in terms of Dowty's prototypical roles augmented with the notion of semantic restrictness used in LFG. No ranking of thematic roles is used in DUG.

In GB, LFG, HPSG and UCG, grammatical relations are viewed as links between (syntactically) selected constituents and  roles. In GB, the thematic functionality of argument structure participants is directly projected in syntactic structure. Grammatical relations such as subject and objects are expressed as predication and government relations between nodes in tree structures. In LFG, HPSG and UCG, grammatical relations are specified in the lexicon. In LFG, this specification is given by the Lexical Mapping Principles which governs the linking of  roles to primitive grammatical function features in lexical forms. In both HPSG and UCG, arguments are syntactically ranked according to the obliqueness hierarchy which reproposes the functions subject, object and indirect object in terms of relative position in the subcategorisation list. In DUG, linking is expressed lexically as elementary form-function units; grammatical functions are viewed as primitives.

Further differences concern the treatment of control and extraposition structures with clausal complements. In GB, both equi and raising verbs subcategorise for a sentence. With equi and subject raising verbs, control is expressed syntactically. The complement subject of equi verbs is an empty category which is syntactically controlled according to the binding theory. With subject raising verbs, the complement subject moves into the matrix subject position to receive case leaving behind a coindexed empty category. Object raising verbs are treated as a case of straight sentential complementation, i.e. no control is involved, since the complement subject is allowed to receive case in situ by the matrix verb. In LFG, HPSG, UCG and DUG equi and raising verbs subcategorise for a verb phrase; control is lexically specified for all, including object raising verbs. A common trait to all is the need to specific the control propensity of a verb (e.g. subject or object control), which is done lexically. Finally, extraposition verbs include lexical specification of the pleonastic subject / object NP in LFG, HPSG, UCG and DUG, but not in GB where the pleonastic NP is inserted in syntax following movement of the argment which is amenable to extraposition.

Table 3.2 provides a schematic summary of the comparison drawn above.

 

Table 3.2: Comparison of subcategorisation in contemporary syntactic theories 

Information Types	GB	LFG	HPSG	UCG	DUG
ARGUMENT STRUCTURE
- Rep. level	syntax	syntax	semantics	semantics	syntax
- ranking	ext/internal	Hierarchy	in prep.	proto-roles	no
GRAMMATICAL RELATIONS
- Gram.   Functions	derived	decomposed into primitives	derived	derived	primitive
- Representation     level	syntax	lexicon	lexicon	lexicon	lexicon
- Linking	predication & govt	Lexical Mapping Principles	obliqueness	obliqueness	form-function units
EQUI/RAISING
- Clausal     complement	sentence	verb phrase	verb phrase	verb phrase	verb phrase
OBJECT RAISING
- Control     expressed	no control	lexically	lexically	lexically	lexically
EQUI/SUBJECT RAISING
- Control     expressed	syntactically	lexically	lexically	lexically	lexically
- Control     propensity	lexically	lexically	lexically	lexically	lexically
EXTRAPOSITION
- Pleonastic NP	introduced in syntax	subcategorised	subcategorised	subcategorised	subcategorised

In addition, all the frameworks reviewed make use of features such as case and verbal form (e.g. infinitive, gerundive) to express morphosyntactic properties of subcategorised phrases. The correspondences resulting from this comparison suggest the following minimal list of general core notions as the edited union of the various basic notions which characterise subcategorisation structure in the frameworks taken into consideration:

Argument structure

-- Predicate and arguments associated with ranked participant roles.

Grammatical relations

-- Linking of arguments in argument structure to grammatical functions governed by participant role functionality.

Equi

-- Controller & controllee are both thematic; control propensity specified lexically.

Raising

-- Only controlled position is thematic.

Expletive Construction

-- Pleonastic argument is found in either subject or object position.

Morphosyntactic features

-- Such as case and verbal form for subcategorised phrases.

We shall see how these general common core notions can be used to develop subcategorisation standards.