This paper is based on a study which was conducted within the research grant ''Institutions in Life Stories. Multilevel Comparative Analysis of Biographical Narratives of Three Groups of Participants in Czech Society in 20th Century''. The aim of this research was both to describe one possible way of using a corpus to identify relevant differences between three types of text (in this case biographical narratives of three groups of speakers: communist officials, dissidents and so-called common people) and to serve as a basis for further analysis (be it a linguistic, sociological or historical analysis). We tried to point out typical features of the language of each group based on the most frequent expressions (nouns, adjectives etc.) and especially collocations. We also compared the corpus Příběhy (Stories) as a whole with the ORAL2008 corpus of synchronic spoken Czech, the SYN2005 corpus of synchronic written Czech and the Totalita corpus (a corpus of communist propaganda).