The evidence for these predictions is extensive, so I will simply summarize some
of the major findings before turning to the predictions Contrast makes about
acquisition.

Evidence for the first prediction comes from the lexicon and from syntax. In
both, differences in form make for contrasts in meaning. Meanings may overlap,
of course, but they nonetheless contrast in at least some contexts. In the lexicon,
many apparent synonyms are in fact not synonymous; they mark contrasts in
dialect, in register, or in connotation. In syntax, differences in form mark dif-
ferences in meaning, but some of these reflect subtle shifts in perspective or
topicalization.

Lexical contrasts. Meaning differences, large and small, are characteristic of
the lexicon. The study of such differences has traditionally been carried out
within semantic fields where linguists have analyzed and characterized patterns
of contrasts (e.g., Bierwisch, 1967; Lehrer, 1974; Lyons, 1963). While different
lexical domains may be organized in a variety of ways, the property they all
display is that each term within a domain or semantic field contrasts in meaning
with all the others. The precise pattern of lexical contrasts will vary with the
internal organization of a semantic field (for discussion, see Fillmore, 1978;
Kay, 1971; Lehrer, 1974; Lyons, 1977).

Possible relations in lexical domains include those among co-hyponyms
(terms contrasting at the same level). For example, horse, dog, cat, and sheep
are all co-hyponyms of terms above them, hierarchically, like mammal or ani-
mal. This relation of hyponymy may hold across two or more levels. Thus
spaniel, a co-hyponym of boxer, Alsatian, and Labrador, is a hyponym of and
contrasts with dog, and dog in turn is a hyponym of and contrasts with animal.

-3-