Noncombinatorial grammar: A challenge for memory research on second language acquisition and bilingualism

Research on second language acquisition has greatly benefitted from the declarative procedural model (DPM). The DPM proposes that declarative and procedural memory support - respectively - the acquisition of the L2 lexicon and L2 grammar. However, over the years, the meaning of 'grammar' and 'lexicon' within the DPM has changed, perhaps as a result of the changes occurred in linguistic theory. In particular, a number of studies coupled the combinatorial rules of grammar supported by procedural memory with patterns of usage and probabilistic rules. Such specifica-tion apparently excluded 'noncombinatorial grammar', which is the grammar computed over frequency-independent features. This paper first discusses the evolution of 'grammar' and 'lexicon' within the DPM, then describes a number of noncombinatorial phenomena that have been overlooked in memory studies on bilingualism. The aim is to encourage future research on whether and how especially procedural memory can also support the acquisition of non -combinatorial grammar.