This edited volume offers an insightful theoretical conceptualization of issues central to 21st century foreign language learning and teaching. Drawing on research results obtained in the fields of pedagogy, social psychology and sociology of education, this book provides a comprehensive practical exploration of issues experienced by researchers in Poland and in Europe, and which can easily find far-reaching implications in other educational contexts. Part I, Focus on the Teacher, includes seven texts discussing topics relevant to teacher initial and in-service education, as well as the functioning of foreign language instructors in educational systems. The eight contributions included in Part II, Focus on the Learner, explore learner-internal and learner-external factors that affect the effectiveness of the language learning process. The exploration of key contemporary  topics and the wide range of methodologies applied make this book of high relevance to Second Language Acquisition scholars, teacher educators,  teachers, and language education policy makers.