This study seeks to investigate what role the knowledge of foreign languages played in the circles of IX–Xth century Hungarians and how it affected the career and fate of individuals. First of all the author comes to the conclusion that, according to the information preserved in the sources, there is no anachronistic difference between the contemporary and present-day ideas of a foreign language and that of the adjoining principles (knowledge of language, interpretation, etc.), therefore research into this theme can be accomplished according to the rules of historical scholarship. Examination of pre-conquest Turkish loanwords proves that the Hungarians obtained these very important words thanks to a certain level of bilingualism, which affected a rather wide layer of the population. Due to the knowledge of Turkish language the Hungarians gained expertise and got to know new procedures and crafts. Besides, the direct relation between the knowledge of languages and the acquisition of new skills can be proved even in this early period. Hereinafter the author of the study illustrates the possibilities of the acquisition of foreign languages with Byzantine sources and examples dating from the conquest period. He also describes the evolution of interpretation skills in this age, while providing specific examples how knowledge of foreign languages affected the fate of individuals. According to the conclusion of the paper, research into contemporary knowledge of foreign languages proves that skills, ideas related to this field had already existed among Hungarians during the IX–Xth centuries (i. e. before the establishment of the Christian state) but these just can be interpreted as distant antecedents of present-day forms. However, their study supports a better understanding of their future development.