This special issue revisits a classic topic in linguistic theory, A-bar movement, applied to developing and bilingual grammars. We claim that A-bar movement, or filler-gap dependencies, is still the quintessential linguistic phenomenon to illustrate the interaction between the biological endowment, the experience with language (past and present),…

There are several theories which tackle predicting the source of third language (L3) crosslinguistic influence. The two orthogonal questions that arise are which language is most likely to influence the L3 and whether the influence will be wholesale or piecemeal (property-by-property). To my mind, Westergaard's Linguistic Proximity Model (LPM) is…

When we think of the debates surrounding linguistic transfer in L3 acquisition, one of the most prominent discussions concerns whether transfer occurs in a wholesale fashion or whether it is property-by-property. One such model is the Linguistic Proximity Model (LPM, Mykhaylyk et al., 2015; Westergaard et al., 2017; Westergaard, 2021), which…

This provocative article raises many important issues that need to be addressed and in so doing will advance the fields of second language (L2) and third language (L3) acquisition in several important ways. Fundamental questions concerning multilingual development persist especially with respect to the role of Universal Grammar in this language…

A generative approach to language acquisition is no different from any other in assuming that target language input is crucial for language acquisition. This discussion note addresses the place of input in generative second language acquisition (SLA) research and the perception in the wider field of SLA research that generative SLA…

The concept of modularity is used to contrast the approach to working memory proposed by Truscott with the Baddeley and Hitch multicomponent model. This proposes four sub components comprising the "central executive," an executive control system of limited attentional capacity that utilises storage based on separate but interlinked…

The extensive literature on subject expression in Spanish makes for rich comparisons between generative (formal) and usage-based (functional) approaches to language acquisition. This article explores how the problem of subject expression has been conceptualized within each research tradition, as well as unanswered questions that both approaches…

This article offers commentary that the Multiple Grammar (MG) language acquisition theory proposed by Luiz Amaral and Tom Roeper (A&R) in the present issue lacks elaboration of the psychological mechanisms at work in second language acquisition. Topics discussed include optionality in a speaker's grammar and the rules of verb position in…

In this commentary, the author defends the Multiple Grammars (MG) theory proposed by Luiz Amaral and Tom Roepe (A&R) in the present issue. Topics discussed include second language acquisition, the concept of developmental optionality, and the idea that structural decisions involve the lexical dimension. The author states that A&R's…

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…

This article offers commentary on the Multiple Grammars (MG) language acquisition theory proposed by Luiz Amaral and Tom Roeper in this issue. It argues that more precise definitions are needed for the terms "rule," "simple," and "productive." Topics discussed include Amaral and Roeper's verb second (V2) rule,…

Amaral & Roeper's Multiple Grammars (MG) proposal offers an appealingly simple way of thinking about the linguistic representations of bilingual speakers. This article presents a commentary on the MG language acquisition theory proposed by Luiz Amaral and Tom Roeper in this issue, focusing on the theory's implications for child…

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…

The novelty of Lardiere's proposal does not reside in her so-called "rehabilitation" of Contrastive Analysis. In generative second language acquisition research, appeal to the best available analyses and descriptions of the languages under investigation has always been a top priority, whether the focus was parameters, functional categories or…