A SYNOPSIS OF ROLE AND REFERENCE GRAMMAR 41ments in the LS of the predicate must appear in the core of the clause.
However, it is not always the case that an argument in the LS occurs in the
core; in a passive construction, for example, the agent or experiencer, if
overt, will be realized as an oblique constituent in the periphery. Among
core arguments a further distinction is made between direct and oblique
core arguments. This contrast is based on the morphological coding of the
arguments: direct core arguments are those that are morphologically
unmarked or coded with a direct case, as in dependent-marking languages
like English and German, or are cross-referenced on the verb, as in head-
marking languages like Lakhota and Tzotzil. Oblique core arguments are
those marked by an adposition or by an oblique case. Thus English give has
three core arguments; in Harry gave Bill the key there are three direct core
arguments, while in Harry gave the key to Bill there are two direct core
arguments and one oblique core argument.^24 This will be discussed in more
detail in sections 4.5-4.6.
The derivation of thematic relations from argument positions in LSs
has a significant consequence: because there are syntactic and semantic
criteria determining the class of a verb and because the thematic relations
which a verb assigns to its arguments are to a great extent attributable to its
class and hence to its LS, the assignment of thematic relations to verbs in
RRG is independently motivated.
In FVV it was argued that it was better to set up a semantic continuum
of thematic relations rather than a fixed universal inventory. Agent defines
one end and patient the other; all of the other thematic relations represent
points along the continuum, and there is no absolute number of distinctions
which every language must make, although there is strong evidence that
certain of these distinctions are universal. The continuum may be rep
resented as in Figure 15. The anchor points of the thematic relation con
tinuum are agent (the willful, volitional, instigating participant) at one end
and patient (the non-willful, non-instigating, maximally affected partici
pant) at the other. In between the endpoints, there is a continuum of