Contradictory information in the input as the cause of Multiple Grammars: Predictions for bilingual acquisition

Publication Summary

The central claim in Amaral and Roeper’s (this issue; henceforth A&R) keynote article is that everyone is multilingual, whether they speak one or more languages. In a nutshell, the idea is that each speaker has multiple grammars or ‘sub-sets of rules (or sub-grammars) that co-exist’. Thus, rather than positing complex rules to account for the intricacies of a given linguistic property, e.g. residual V2 in English, the theory of Multiple Grammars (MG) posits that speakers have several simpler rules which operate in parallel, something which the authors argue is more in keeping with minimalist grammar. The source of these multiple grammars is contradictory information in the input to the language-learning child. Even in monolingual societies, the authors claim, children are regularly provided with conflicting input as a result of, for example, language change and lexical exceptions to (morphosyntactic) rules. After developing multiple grammars to cope with this, children then use ‘linguistic cues to figure out which of [their] sub-grammars are dominant and productive, and which ones are lexically motivated and idiosyncratic’. The claim that adult speakers and/or language-learning children may have multiple grammars at their disposal is not new: Roeper (1999), in an earlier incarnation of MG dubbed Universal Bilingualism, and others (e.g. Kroch and Taylor, 1997; Yang, 2002) have used the notion of co-existing or multiple grammars to account for dialectal variation, diachronic language change and variation in first language (L1) acquisition. In the keynote article, A&R turn to (adult) second language (L2) acquisition, claiming that multiple grammars are ‘the primary source for optionality in all stages of adult L2 acquisition’.