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),…

Eye tracking has become an increasingly popular research methodology among language researchers to examine online cognitive processing of second-language (L2) speakers and bilinguals. As the scope of eye-tracking research expands, there is a need to ensure that the methodology is used properly, so as to safeguard the validity of research findings…

In this paper, we review how eye tracking, which offers millisecond-precise information about how language learners orient their visual attention, can be used to investigate a variety of processes involved in the multifaceted endeavor of second language acquisition (SLA). In particular, we review the last 15 years of research in SLA, in which…

Lexical knowledge is complex, multidimensional, and difficult to pin down to a set of defined components. The development, organization, and use of lexical knowledge in the first and additional languages are studied in a number of neighbouring disciplines beyond second language acquisition and applied linguistics, including psycholinguistics,…

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 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…

With eye-tracking technology the eye is thought to give researchers a window into the mind. Importantly, eye-tracking has significant advantages over traditional online processing measures: chiefly that it allows for more "natural" processing as it does not require a secondary task, and that it provides a very rich moment-to-moment data…

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…

As in any field of scientific inquiry, advancements in the field of second language acquisition (SLA) rely in part on the interpretation and generalizability of study findings using quantitative data analysis and inferential statistics. While statistical techniques such as ANOVA and t-tests are widely used in second language research, this review…