We investigated how positive, negative, and neutral mood states influence aspects of second language acquisition, either directly or in interaction with certain personality characteristics (openness, intuition, emotional intelligence, foreign language anxiety, and impulsivity). After completing individual differences questionnaires, 120 participants were randomly assigned to either a Comparison group or one of three emotionally induced treatment groups. They were trained on a semiartificial language under incidental learning conditions. Immediate testing measured participants' knowledge of the target syntactic forms, while source-attribution data gauged the nature (implicit, explicit, or a combination of both) of their knowledge. Contrary to some previous studies, knowledge gains were chiefly conscious-explicit. Participants exhibited substantial variability in how emotions impacted their learning, with self-reported stress management and premeditation resulting in higher learning in the Negative group. Overall, participants that claimed higher levels of intellect showed the best results.