Vocabulary Studies in L1 and L2 Development

This Special Issue presents twelve papers examining vocabulary development across first- and second-language contexts, emphasizing the dynamic link between theory and classroom practice. Key topics include the influence of first-language (L1) knowledge on second-language (L2) vocabulary acquisition, the creation and validation of innovative vocabulary assessment tools, and the effectiveness of instructional strategies for promoting lexical growth. A central theme is the interaction between L1 and L2 vocabularies. Several contributions explore how learners’ L1 knowledge shapes L2 vocabulary learning, highlighting cross-linguistic influences and strategies for leveraging L1 resources to enhance L2 acquisition. This underscores the importance of understanding inter-lingual connections for effective teaching. The Issue also advances research on vocabulary assessment by introducing novel methods for measuring lexical knowledge and its relationship to broader language skills, such as reading comprehension. As such, it provides valuable frameworks and practical tools for educators and researchers. Additionally, the collection includes investigations into instructional approaches such as spaced repetition and digital annotation, as well as cognitive factors such as working memory. These studies show how targeted strategies can improve vocabulary retention and acquisition, offering insights for differentiated instruction.