Complex Dynamic Systems Theory (CDST) has received considerable attention over the last decades, inspiring a number of second language acquisition studies. This article examines the research from a critical epistemological point of view, starting from the Greek philosopher Cratylus, who concluded that remaining silent is the only way to be…

In this commentary to Westergaard (2021), we focus on two main questions. The first, and most important, is what type of L3 data may be construed as supporting evidence--as opposed to a compatible outcome--for the Linguistic Proximity Model. In this regard, we highlight a number of areas in which it remains difficult to derive testable predictions…

This article proposes a novel account for the overuse of free morphemes and underuse of bound morphemes in English as a second language (L2) based on the framework of Distributed Morphology. It will be argued that an Economy Principle 'Do everything in Narrow Syntax (DENS)' operates in the L2 learner's computational system. Consequently,…

We evaluated external and internal sources of variation in second language (L2) and native language (L1) proficiency among college students. One hundred and twelve native-English L2 learners completed measures of L1 and L2 speaking proficiency, working memory, and cognitive control and provided self-ratings of language exposure and use. When…

Construct validity and building validity arguments are some of the main challenges facing the language assessment community. The notion of construct validity and validity arguments arose from research in psychological assessment and developed into the gold standard of validation/validity research in language assessment. At a theoretical level,…

Recent approaches to the "that"-trace phenomenon in English include syntactic analyses based on the principle of Anti-locality and a sentence production analysis based on the Principle of End Weight. These analyses have many similarities, but they differ in their predictions for second language (L2) speakers. In an Anti-locality…

This text comments on the Keynote article 'Microvariation in multilingual situations: The importance of property-by-property acquisition' by Marit Westergaard, who argues for Full Transfer Potential within the Linguistic Proximity Model in third language (L3) acquisition. The commentary points at some theoretical and methodological issues related…

This article enters the debate about the complex and dynamical nature of second language acquisition (SLA) by discussing and commenting on Pallotti's critique of Complex Dynamic Systems Theory (CDST). Pallotti's critique brings to the fore the argument that, due to its anti-reductionist stance, CDST research fails to observe three fundamental…

Multilingual research could offer a unique perspective on how the languages already acquired by a person affect the online processing of a new language. But it is currently difficult to assess this issue because theoretical accounts of multilingualism have focused on acquisition rather than processing and most empirical research to date has…

As a personality trait, second language (L2) grit--a combination of perseverance and passion for L2 learning--has recently been proposed as a meaningful predictor of learners' motivational behavior and L2 achievement. The results of a growing body of empirical studies carried out in various L2 contexts have substantiated the power of L2 grit in…

In this article I am going to review the 'progress' which L2 materials development has made both as a practical pursuit and as an academic discipline since my first contact with materials development in the 1960s. I am also going to evaluate the current situation, to make predictions about future developments and to make recommendations to…

This article proposes a formal model of the human language faculty that accommodates the possibility of 'attrition' (modification or loss) of morphosyntactic properties in a first language. Modeling L1 grammatical attrition entails a quite fundamental paradox: if the structure of the language faculty in principle allows for attrition of…

A large dataset of word recognition behavior from nonnative speakers (NNS) of English was collected using an online crowdsourced lexical decision task. Lexical features were used to predict NNS lexical decision latencies and accuracies. Predictors of NNS latencies and accuracy included contextual diversity, age of acquisition, and contextual…

The declarative/procedural (DP) model posits that the learning, storage, and use of language critically depend on two learning and memory systems in the brain: declarative memory and procedural memory. Thus, on the basis of independent research on the memory systems, the model can generate specific and often novel predictions for language. Till…

Historically, first language acquisition research was a painstaking process of observation, requiring the laborious hand coding of children's linguistic productions, followed by the generation of abstract theoretical proposals for how the developmental process unfolds. Recently, the ability to collect large-scale corpora of children's language…