This study investigates the role of age of first exposure in the acquisition and processing of English articles in an EFL setting. Fifty advanced Korean learners of English participated in a grammatical acceptability judgment task and a self-paced reading task. The participants were divided into two groups depending on the initial age at which they were constantly exposed to English at least 3 hours per week (‘early group’ < 12; ‘late group’ ≥ 12). No significant performance differences were observed between the two groups in the judgment task. However, meaningful differences were found between the reading behaviors of the two groups in the self-paced reading task. These findings show that the learners’ age of first exposure has a significant impact on learners’ performance when the ability to process English articles in real-time is evaluated. In contrast, it has much less impact on learners’ performance on a task which tests explicit knowledge under no time-limit condition.