Abundant research has indicated fluency features as meaningful predictors of second language proficiency. However, the extent to which different fluency dimensions and features can predict proficiency remains underexplored. This meta-analysis employed a multilevel modeling approach to synthesize fluency-proficiency relationships from 71 empirical…

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…

Most second language acquisition (SLA) research has documented the processes involved in learning second/foreign languages, with few studies focusing on the durability of attained second language (L2) skills once instructed learners/users are no longer receiving formal instruction. The current study examines the effects of continued exposure and…

This cross-sectional study examines the sociopragmatic use of pitch and fluency features in requests among second language (L2) Chinese learners at two proficiency levels alongside native Chinese speakers. Twenty-eight L2 learners completed a 40-item oral discourse task with two types of request-making situations: (a) a high-imposition request to…

A handful of second language (L2) studies have explored "bidirectional pragmatic transfer": "forward pragmatic transfer"--the influence of learners' first language (L1) on their L2--and "reverse pragmatic transfer"--the impact of learners' L2 on their L1. This explanatory sequential mixed-methods study investigated…

Current L2 utterance fluency literature tends to operationalize disfluency as isolated, individual features. However, disfluency features often co-occur at one location or across multiple locations in one utterance. This study explores the co-occurrence of L2 disfluency features in a speech corpus from 71 L1 and L2 speakers of English across…

This study examined the influence of cognate status and language distance on simultaneous bilingual children's vocabulary acquisition. It aimed to tease apart effects of word-level similarities and language-level similarities, while also exploring the role of individual-level variation in age, exposure, and nontarget language proficiency. Children…

This study investigated the use of Artificial Intelligence (AI) models and signal detection processes to generate meaningful visual and ChatGPT-like narrative feedback on second language (L2) English intelligibility. To test the effects and perceptions of such techniques, three groups of learners (N = 90) received visual and narrative feedback…