A number of international studies indicate a link between competence in the mother tongue and competence in a second language. However, most research has focused on adolescent and adult learners, leaving out the early stages of second language learning, and has examined the linguistic and cognitive components without addressing the role of emotions experienced in the learning context. To this end, 182 second and third grade primary students took part in this study, during which their level of proficiency in Italian vocabulary (as mother tongue), their level of proficiency in English (as second language) and their perceived emotions in English learning contexts were measured. Considering the entire sample, significant correlations were found, positive between performance in Italian and the emotion of Joy, and negative between performance in English and the emotions of Boredom and Anxiety. Furthermore, in line with expectations, regression analysis showed that age, performance level in mother tongue and anxiety significantly predicted performance in the second language. Considering, on the other hand, the sub-sample composed of participants with extreme performance in the mother tongue (< 25th and >75th percentile), it emerged that the two groups did not differ for any of the measured emotions, but the mother tongue high-performance group reported significantly higher performance in all parameters related to English. Learning English as a second language in Italian primary school children appears to be related to the competence achieved in the motor tongue, in agreement with the literature that has examined secondary school or university students and adults, and is also explained by the level of anxiety, which negatively predicts learning. However, the comparison between groups with high and low competence in Italian, shows for the latter only worst performance in English but no differences in the emotions experienced in learning contexts. Future studies should investigate such differences in the role played by emotions in the general population and in students with extreme performance in their mother tongue. [ABSTRACT FROM AUTHOR]