This book features critical and interpretive, linguistic perspective on foreign language teaching and learning in the 21st century Poland. By juxtaposing two conceptions of identity: essentialist and poststructuralist, the author attempts to present the problem of an EFL teacher identity construction and performance. Language is key to the study, both as a methodology for making more evident how identity operates through discourses and also as the object being studied. The author brings together these two dimensions of language with attention to both the specifics of participants' words and to the wider frames of discourse. The two conceptions of identity are discussed on the basis of the research conducted in one community of practice, i.e. Polish teachers of English. The results of the study lead to the conclusion that an EFL teacher identity should be recognized as an individual self-concept that is (re)fashioned every time individuals engage in interactions with varied milieus.