The internal/external (I/E) frame of reference entails high, positive association of mathematics and verbal achievements with matching academic self-concepts but negative or near-zero correlation with their nonmatching self-concepts. This study aimed to extend the traditional I/E model by contrasting the mathematics domain with two foreign languages (English and Russian). A total of 540 Azeri eighth-grade students participated in this study. Confirmatory factor analysis revealed distinct domain-specific self-concepts for two foreign languages and mathematics, indicating a negative or near-zero nonsignificant correlations between academic self-concepts and nonmatching achievement domains but high positive, significant correlation between academic self-concepts and matching achievement domains. This study revealed distinct domain-specific self-concepts for two foreign languages, indicating a negative or near-zero nonsignificant correlations between verbal self-concepts and nonmatching verbal achievement domains. It was difficult to form a single verbal domain. The findings could be used to inform the design of interventions to improve learners' academic self-concept and achievement.