Adjectival modification
Adjective–noun constructions exhibit a number of restrictions. First, a number of languages do not have a distinct category of adjectives—hence there is no construction of this kind. And second, such constructions also show constraints on recursion in some languages, allowing simple but no productive recursion.
One way in which adjectival notions may be expressed is via the relativization of verbs; thus, in the Ik language of northeastern Uganda, qualities such as ‘big’, ‘red’, or ‘good’ need to be encoded by means of relativizing verbs of state, for example dε-Ika nı̒ ze-ı̒ka (foot-PL REL.PL be.big-PL) ‘big feet’. Since relative clauses are already recursive, we will ignore this kind of structure.
Instead, of central interest here is a process to be observed in quite a number of languages where two nouns are juxtaposed—with the effect that one of them is grammaticalized to an adjectival modifier while the other is the head of the construction—accordingly, a structure such as (13a) is grammaticalized to a recursive structure (13b) (see “The first layer: nouns”).
In this way, nouns for ‘man’ and ‘woman’ tend to acquire characteristics of adjectives in many languages, taking the position of adjectives and denoting ‘male’ and ‘female’, respectively. Semantic domains that are cross-linguistically most likely to undergo grammaticalization from noun to adjective are those of plants, animals, and metals, cf. English a pink dress, a silver pot. Grammaticalization involves (a) extension, in that a given noun is moved from the canonical position it occupies as a referential noun to a position next to another noun, (b) desemanticization, in that the nominal meaning is reduced to some semantic property of color, sex, size, etc., and there is also (c) decategorialization since that noun loses salient morphosyntactic properties of nouns, such as taking its own modifiers, determiners, and inflections.
That the directionality is generally one from noun-to-noun modification is also in accordance with evidence from child language development: Children learn nouns before they proceed to acquire noun modification. Conversely, we are not aware of any convincing evidence to suggest that young children start out producing modified nouns before they learn nouns in isolation. English-speaking children acquire simple nouns typically before age 2, while modifier–noun structures, such as possessive noun (your hand) and adjective–noun phrases (a brown car) are produced only between age 2 and 2;6 (Valian 1986; Tomasello 2003a: 208). The fact that these children consistently place adjectives before, rather than after, nouns might suggest that they do have some knowledge of the taxonomic relationship between the two entities—that is, that already at this age they use this as a hierarchical structure ([A] B) rather than as a shallow, juxtapositional ‘‘island’’ structure (A–B).
