1 Adjective Classes in Typological Perspective 45tives may have both functions. A separate parameter concerns whether, when an
adjective occurs in an NP, it may take some or all of the morphological processes
available to nouns; if it does it is 'noun-like', if not 'non-noun-like'. There is a cor-
relation—but not a coincidence—between being 'non-verb-like' and being 'noun-
like'. In some languages, adjective classes are both 'verb-like' and 'noun-like', and in
some they are both 'non-verb-like' and 'non-noun-like'.
It can sometimes be a tricky matter finding criteria to distinguish 'verb-like'
adjectives from verbs, or 'noun-like' adjectives from nouns. I believe that in every
language which is studied in detail, such criteria can be found. Criteria are not
always of the definitive 'yes-or-no' variety; as Alpher (1991) shows for the Austral-
ian language Yir-Yoront (see §5), a collection of statistical tendencies can combine
to provide a satisfactory grammatical characterization of the adjective class (as
opposed to noun and verb classes).
As in every other aspect of linguistic criteria, the parameters and classifications
are not watertight. For example, the degree to which adjectives are 'verb-like' or
'noun-like' varies from language to language. And although for most lexemes in
a language their grammatical class membership can be unambiguously assigned,
there are always likely to be a few fuzzy areas between classes (Dixon 1988: 239-40
illustrates this for Fijian).
In §9 a tentative correlation was established: non-verb-like adjective class-
es tend to be found in languages with dependent-marking at clause level, with
verb-like adjective classes being typically found in languages with head-marking
or with neither dependent- nor head-marking. I suggested, with some support-
ing exemplification, that if a language shifts its head-/dependent-marking profile,
then the orientation of its adjective class is likely slowly to change, to re-establish
the correlation.
Finally, §10 looked briefly at the kinds of semantic overlap between the three
major word classes. We saw that English has considerable verb/noun and adjec-
tive/noun but rather little verb/adjective overlap, while Dyirbal is almost exactly
the reverse, with considerable verb/adjective but no verb/noun or adjective/noun
semantic overlap.
ReferencesABBOTT, MIRIAM. 1991. 'Macushi', pp. 23-160 of Handbook of Amazonian languages,
Vol. 3, edited by Desmond C. Derbyshire and Geoffrey K. Pullum. Berlin: Mouton de
Gruyter.
AIKHENVALD, ALEXANDRA Y. 1998. 'Warekena', pp. 225-439 of Handbook of Amazonian lan-
guages, Vol. 4, edited by Desmond C. Derbyshire and Geoffrey K. Pullum. Berlin: Mou-
ton de Gruyter.
- Language contact in Amazonia. Oxford: Oxford University Press.
ALPHER, BARRY. 1991. Yir-Yoront lexicon: sketch and dictionary of an Australian language.
Berlin: Mouton de Gruyter.
ARNOTT, D. W. 1970. The nominal and verbal systems ofFula. Oxford: Clarendon Press.