The half module provides an introduction to key concepts used in research on language development throughout the lifespan. Topics will include monolingual and bilingual child language acquisition, second language acquisition by child and adult learners, language loss through aphasia or dementia, and the attrition of the first language in second language learners. The module will provide students with an overview of research findings from a broad range of studies, including ongoing studies in the Centre for Language Development throughout the Lifespan (LaDeLi) at the University of Essex.