Individual multilingualism involving the learning and using of different languages and linguistic varieties is a common phenomenon often encouraged by policy makers in many Western countries. A key measure has been the widespread implementation of foreign language (FL) teaching in primary education. Mainstream primary schools typically cater for a diverse student population, including those with special educational needs (SEN). While educational policies emphasise inclusive learning environments, ensuring equal access to FL education remains a challange equal access to FL education remains a challenge for institutions and teachers. Investigating individual learner dispositions can enhance our understanding of the FL learning experiences of students with SEN and inform intervention and support strategies. This chapter presents a longitudinal investigation of individual differences (IDs) consistently associated with successful FL learning, specifically language aptitude and affective dispositions (intrinsic FL motivation, FL anxiety, FL self-concept). Data were collected from 451 learners of L2 English aged 10–12 years using adapted subtests of the MLAT-E and PLAB to assess language-analytic ability, along with a motivational questionnaire administered at three time points over two academic years. Results show that children with SEN (n = 83) scored lower on the MLAT-E and PLAB and exhibited less positive FL self-concepts, had lower FL intrinsic motivation, and reported higher levels of FL anxiety. Overall, differences between children with and without SEN remained stable, except in inductive ability (PLAB), where children without SEN made slightly more progress.