AbstractMuch research exists on the role of textual enhancement in instructed second language (L2) development, yet little is known about how its effectiveness is influenced by multiple exposures, whether it can facilitate the acquisition of L2 derivational morphology, and how it may affect child language learning. To fill these gaps, this study employed a six‐week multiple‐exposure design to investigate the extent which to textual enhancement can benefit children’s knowledge of L2 derivational morphemes. The study employed a pretest‐posttest design, with six treatment sessions. Participants were 91 L2 learners of English in two primary school EFL contexts (Romania, Sweden). In each context, participants were randomly assigned to two groups: the +highlight group received textually enhanced texts, whereas the –highlight group read unenhanced texts during the treatment. The children read the texts through a digital reader application during their English lessons. The target constructions were the –ion and –ment morphemes. The pretest and posttest included a non‐word derivational suffix choice and a nonword derivational suffix decomposition task. Results of linear mixed effects models found a small advantage of textual enhancement for the acquisition of the –ion morpheme by Swedish learners on the suffix choice task, but Romanian learners showed no benefits from highlighting.