In this final article in this guest-edited issue on synergies in second language acquisition and teaching (SLA/T), we attempt to bring together the main content of this issue in an overall, combined synergy statement, concluding this project as a whole. Let us remind readers of the project: A shared effort by 17 scholars taking 11 different…

This article presents a theoretical review of and methodological guidelines for the study of two key notions in second language acquisition research, complexity and difficulty. The term "complexity" has gained considerable currency over the past decades and has taken on a wide range of meanings. We argue for a more restricted…

In this Methods Showcase Article, we illustrate mixed-effects modeling with a multinomial dependent variable as a means of explaining complexities in language. We model data on future-time reference in second language Spanish, which consists of a nominal dependent variable that has three levels, measured over 73 participants. We offer step-by-step…

Background: Vocabulary learning is an essential dimension of foreign language learning. The learners have a huge responsibility in this task. Among other factors, time constraints and an overall lack of maintained motivation on the part of students makes it especially challenging. Consequently, improving vocabulary learning requires strategies to…

This project studies how Spanish-Catalan early bilinguals use language learning strategies (LLS) differently depending on their order of language acquisition when they are learning French as an L4. Considering that the use of LLS has been pointed out as a sign of successful language learning, the study inquires whether being a simultaneous…

The perception of the teacher as the authority in the classroom is deep-rooted in education yet this notion seems to contradict the fundamental values of democratic education. Schools grant teachers an abundance of authority and decision-making power. The pedagogical implications of how teachers use this power in the classroom are not…

In this meta-analysis, we examined the average correlations (weighted for sample size and corrected for measurement error) between the varied types of motivation specified within self-determination theory (SDT) and second language (L2) achievement. We also conducted moderator analyses to explore whether these relationships are influenced by age,…

In the last decades, the field of applied linguistics has called for an expanded knowledge on language learning in different learner groups and contexts, including forced migrants and low-literate learners. This article focuses on an under-studied learner group in an under-studied context: low literate adult refugees (LESLLA) subjected to language…

Purpose: This meta-analysis study aimed to determine the optimal level of talker variability in training to maximize second-language speech learning. Method: We conducted a systematic search for studies comparing different levels of talker variability in nonnative speech training, published through July 2024. Two independent reviewers screened…

Second language acquisition (SLA) researchers have long searched for patterning in the development of linguistic elements (e.g., grammar and morphology). However, little attention has been given to the examination of systematicity in vocabulary acquisition, limiting our understanding about how overall vocabulary is learnt. The current study…

This study investigates the developmental trajectory of progressive construction among Chinese and Japanese EFL learners through a usage-based approach. A total of 600 written essays, produced by EFL learners from China and Japan with proficiency levels ranging from elementary to upper-intermediate, were analyzed. The findings reveal that advanced…

The use of social media in human life recently is such normal direct interaction including in English language teaching. Politeness strategies are essential in social communication to keep convenient connections. This study aims to examine how politeness strategies are used in increasingly complex situations, combining social media and the…

This study explores the integration of advanced AI technologies, including emotion detection and adaptive learning systems, to enhance second language acquisition among 274 English as a Foreign Language (EFL) learners. Utilizing a pretest-posttest randomized control trial, the research evaluates the effects of AI-enhanced interventions on…

Constructing personalised and effective online language learning models based on individual personality differences is crucial in the field of education. However, there is little research on how to apply these models to students in science and engineering who have varying personality profiles. This study aimed to assess the validity of the Online…

People use different communication patterns based on the context and who they are addressing. These differences, known as linguistic register, are common across human speech and recognized early in development. Here, we examine 4-11-year-old American children's (N = 227) ability to use linguistic registers to determine a speaker's addressee as…