Objective: Attention Deficit Hyperactivity Disorder (ADHD) is one of the most prevalent behavioural disorders among children in which L1 impairments are often displayed. There is a conventional assumption that ADHD-diagnosed children experience difficulties in L2 development as well. The present research aimed at investigating possible L2-related behaviours of ADHD-diagnosed children.Methods: To track L2 profiles among ADHD children, this mixed methods study examined L2 learning performance of ADHD-diagnosed children in terms of English phonological, lexical, and syntactic development compared with typically developing children. To this end, 10 ADHD-diagnosed and 10 typically-developing children were recruited from a public primary school located in Kerman, Iran, throughout the 2022-2023 academic year. The participants were then assigned to two experimental groups and given the English instructions with the same instructor. Results: The quantitative results showed that ADHD-diagnosed learners underperformed the typically-developing learners in all phonological, morphological, and syntactic production and recognition tests. However, the only significant difference was in the phonological recognition test (p = 0.04). Also, the qualitative results demonstrated that both groups were almost equally engaged in classroom interactions.Conclusion: The findings highlighted the importance of speech processing and sustained attention in lexical and syntactic learning ability among ADHD students. The implications of the study for L2 instructors were discussed.
