When acquiring the English plural, children correctly produce plural words long before they develop an understanding of morphological structure. When acquiring Sesotho noun prefixes, children are aware of the multiple constraints governing variation from a young age. Both of these cases raise questions about the Shin and Miller (2022) account of…

In this commentary, I question Westergaard's argument that third language (L3) data can be used to decide between theories such as Full Transfer Full Access, involving wholesale transfer initially, and Full Transfer Potential, involving property-by-property transfer. I suggest that much L3 data will be amenable to explanation under either theory.…

This commentary discusses the issue of small samples in instructed second language acquisition research. We discuss the current state of affairs, and consider the disadvantages of small samples. We also explore other considerations regarding sample size, such as research ethics and ecological validity. We present a range of recommendations for…

This article is a response to commentaries on the article, "Microvariation in Multilingual Situations: The Importance of Property-by-Property Acquisition" (EJ1300541). This response is divided into sections focusing on the following issues: (1) full transfer and the notion of copying; (2) the definition of linguistic proximity; (3) some…

This commentary discusses some theoretical and methodological issues related to research on the spacing effect in second language acquisition research (SLA). There has been a growing interest in SLA in how the temporal distribution of input might impact language development. SLA research in this area has frequently drawn upon the rich field of…

This article is a personal reflection about the acknowledgement of my "taken-for-granted frames of reference" (Mezirow, 2003, p. 59), which were replicating the hegemonic narrative I grew up surrounded by as a white, Mexican, Spanish-speaker; while hindering a more thorough understanding of the educational and linguistic topics that…

This commentary discusses Westergaard's (2021) keynote article, which presents a comprehensive model of first language (L1), second language (L2), and third language (L3) acquisition. The commentary presents evidence from a previous study of L3 learners that provides support for Westergaard's property-by-property transfer proposal. The commentary…

Professor of Second Language Acquisition (SLA) Robert DeKeyser is from the School of Languages, Literatures, and Cultures at the University of Maryland. His research builds bridges between the theory of second language acquisition with major concerns in cognitive aspects such as implicit and explicit learning mechanism, age differences, and…

In volume 103 of "Modern Language Journal," Stephen May suggested that the "multilingual turn" has not fully delivered on its promises, pointing out second language acquisition (SLA) researchers' continued focus on parallel monolingualisms rather than on dynamic bi/multilingualism, the lack of theorization of historicity in…

This article responds to Jordan and Gray's critique of the global coursebook and the call to have open, critical discussions about coursebook use in light of SLA research (Jordan and Gray 2019). I?make a case for why the assumptions made about what constitutes a global coursebook are too narrow. I?also dismiss the idea of one type of global…

In this short article I try to present a taxonomy of sources of difficulty, in particular complexity. I emphasize how these factors interact with each other and with individual differences and treatments, before illustrating some of these interactions and the methodological issues involved in studying them with examples from the empirical studies…

James P. Lantolf is George and Jane Greer Professor Emeritus of Language Acquisition and Applied Linguistics and former director of the Center for Advanced Language Proficiency Education and Research at the Pennsylvania State University, USA. He is currently Adjunct Professor of Applied Linguistics in the same academic unit at Xi'an Jiaotong…

This commentary offers a brief reflection on the state of CALL in 1997, when "Language Learning & Technology" was launched with my paper entitled "CALL in the year 2000: Still in search of research paradigms?" The point of my 1997 paper was to suggest the potential value of research on second language learning for the study…

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…

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…