The bilingual mental lexicon and speech production process.

The Chinese/English intrasentential code-switching data provide evidence that the bilingual mental lexicon involves language contact between language-specific semantic/pragmatic feature bundles. Lemmas in the mental lexicon are tagged for specific languages and contain semantic, syntactic, and morphological information about lexemes. In a bilingual mode, the speaker makes choices at the preverbal level of lexical-conceptual structure, and these choices activate the lemmas in the mental lexicon for the speaker's preverbal message to be morphosyntactically realized at the functional level of predicate-argument structure. The result will be language-specific surface forms at the positional level of morphological realization patterns. The languages involved in the bilingual's mixed speech are never equally activated, with one language projecting the sentential frame and the other supplying a particular type of morphemes for the speaker's communicative intentions. Copyright 2002 Elsevier Science (USA).