The thesis deals with language ideologies in Czech public discourse. After introducing its topic, motivation and structure in the opening chapter, it devotes the second chapter to a thorough analysis of the research field of language ideologies. It presents various ways of defining them, two different approaches to them and a few key features which characterize language ideologies. The relation of language ideologies and other related notions is outlined, possibilities and ways of investigation are surveyed. Some remarks focus on existing lists or glossaries of language ideologies. The core of this chapter is an original, complex definition of language ideologies grounded in a critical reflection of approaches up to now. The third chapter summarizes relevant existing findings and on that basis, it formulates the main aim of the thesis - to make a contribution to knowledge on the foundations and ways of conceptualizing language in Czech public discourse. The fourth chapter elaborates the methodological frame of the thesis. Critical discourse analysis is chosen as a basis - its basics are summarized, main critical comments are considered and a partial solutions are proposed in use of corpus linguistics' tools. Another part of this chapter concerns with keyness as one of the dominant principles used...