We used event‑related potentials to investigate how markedness impacts person agreement in English‑speaking learners of L2‑Spanish. Markedness was examined by probing agreement with both first‑person (marked) and third‑person (unmarked) subjects. Agreement was manipulated by crossing first‑person subjects with third‑person verbs and vice‑versa. Native speakers showed a P600 for both errors, larger for “first‑person subject + third‑person verb” violations. This aligns with claims that, when the first element in the dependency is marked (first‑person), the parser generates stronger predictions regarding upcoming agreeing elements via feature activation. Twenty‑two upper‑intermediate/advanced learners elicited a P600 across both errors. Learners were equally accurate detecting both errors, but the P600 was marginally reduced for “first‑person subject + third‑person verb” violations, suggesting that learners overused unmarked forms (third‑person) online. However, this asymmetry mainly characterized lower‑proficiency learners. Results suggest that markedness impacts L2 agreement without constraining it, although learners are less likely to use marked features top‑down.