Foreign language education is essential for professional development, yet the factors influencing successful language learning vary significantly. This monograph examines these factors and predictors based on both theoretical and methodological perspectives. While interest in this area has grown, further research is needed on aspects like the affective domain, cognitive structure, and willingness to communicate in a foreign language. The work discusses how willingness to communicate serves as a key predictor of success in language education across various contexts. The monograph is structured into two main sections: theoretical and methodological. The theoretical section analyzes selected factors impacting foreign language learning, including self-esteem, anxiety, cognitive structure, motivation, confidence, and willingness to communicate. It also explores the interrelations among these factors, assessing their stability and dynamism as predictors of success. The third chapter focuses on measuring interventions in foreign language education. The practical part of the monograph presents results from individual research studies, highlighting the significance of these findings in understanding the predictors of success in foreign language learning.
