Amaral and Roeper (this issue; henceforth A&R) argue that all speakers -- regardless of whether monolingual or bilingual -- have multiple grammars in their mental language representations. They further claim that this simple assumption can explain many things: optionality in second language (L2) language behaviour, multilingualism, language…

This article offers the author's commentary on the Multiple Grammars (MG) language acquisition theory proposed by Luiz Amaral and Tom Roeper in the present issue. Multiple Grammars advances the claim that optionality is a constitutive characteristic of any one grammar, with interlanguage grammars being perhaps the clearest examples of a…

Optionality is a central phenomenon in second language acquisition (SLA), for which any adequate theory must account. Amaral and Roeper (this issue; henceforth A&R) offer an appealing approach to it, using Roeper's Multiple Grammars Theory, which was created with first language in mind but which extends very naturally to SLA. They include…

This article offers the author's commentary on the Multiple Grammar (MG) language acquisition theory proposed by Luiz Amaral and Tom Roeper in the present issue and touches on other second language acquisition research. Topics discussed include the concept of second language (L2) optionality, a hypothesis regarding the acquisition of the…

This article examines the Multiple Grammars (MG) theory proposed by Luiz Amaral and Tom Roeper in the present issue and presents a critique of the research that went into the theory. Topics discussed include the allegation that the bilinguals and second language learners in the original article are primarily students in an academic setting, Amaral…