The Acquisition of Functional Categories : Data from Japanese

While demonstratives and other determiner-like words in English are part of the functional system, their Japanese counterparts are simple lexical categories. The semantic theory (e.g. Brown & Fraser 1963) predicts that these elements must emerge at a later stage in both languages since they denote relatively abstract and complex meanings; whereas Radford's (1990) maturational theory makes no such predictions about Japanese. In replicating O'Grady's (1993) Korean study, I collected both production and comprehension data for Japanese. The data indicates that despite their categorial status (i.e. lexical categories), these determiner-like elements emerge quite late. Since the late emergence of these elements in both Japanese and English can be attributed to their relatively abstract semantics, there is no reason to attribute the late acquisition of English determiners to their categorial status (i.e. functional categories). Thus, just like O'Grady's Korean data, the Japanese data seems to support the semantic theory.