536 JAMES K. WATTERS
1. Layered structure of the clause
Some of the central claims about language in F&VV are based on what they
call the "layered structure of the clause". They claim the clause is hierarchi
cally structured in the following way: a nucleus, consisting of the verb; a
core, which includes the nucleus and the core arguments (subject and
object(s)); and a periphery, which includes the core and the clausal argu
ments such as temporals and locatives. Something like this is at least
implicit in numerous other approaches to language. For example, the core
corresponds for the most part to the verb and the nuclear terms in Rela
tional Grammar; in Government and Binding theory, it includes all those
arguments involved in the extended projection principle (i.e., the argu
ments for which the verb is subcategorized plus the subject); in the Tag-
memic analysis of Pickett (1959) the core largely corresponds to the "nu
cleus" and the periphery to "periphery" or "satellite" tagmemes (in more
recent versions of tagmemics, e.g., Pike and Pike (1982), the corresponding
units are "clause" and "sentence"); in Dik's Functional Grammar (1978) his
"nuclear predication" and "satellites" roughly match the core and
periphery, respectively, of F&VV.
However, unlike the models above, F&VV make three central claims
regarding this hierarchical structure of the clause. First, they say each layer
has its own set of operators which have scope over that layer: the nuclear
operators are aspect and (for some languages) directionals; the most com
mon core operator is modality; and the clausal operators, in order of
increasing scope, are status, tense, evidentials, and illocutionary force.
(Some of these terms are discussed below.) The following displays the items
relevant to this paper (from a similar diagram in Van Valin 1984):Figure 1