Abstract
<jats:title>Abstract</jats:title> <jats:p> The number of children aged 4–12 (or through the end of primary school) who learn an additional language (AL) beyond their home language(s) is steadily increasing worldwide. Some learn an AL as the medium of schooling in immersion contexts, traditionally considered second language (L2) learning, while others study it as a subject in instructional settings, traditionally considered foreign language (FL) learning. Despite such differences, important commonalities should guide educators when assessing young language learners (YLLs). This article highlights two critical dimensions: (a) age‐appropriateness and (b) learning as the central purpose of assessment. YLLs are still developing cognitively, socially, and affectively, while also continuing their first or home language development. Therefore, attention to age‐related issues in assessment is essential. Moreover, although assessments can serve multiple functions, in the case of YLLs, they should prioritize supporting children's ongoing learning (assessment <jats:italic>for</jats:italic> learning) rather than solely focusing on accurately measuring performance or ability. This article explores how these principles—attending to age and emphasizing learning—shape every stage of assessment, from design and implementation to interpretation and use of results. Finally, because research on assessing YLLs remains more limited than that on adults, the article suggests directions for future inquiry. </jats:p>