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 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…