The aim of this thesis is to acquire a deeper knowledge of Swedish social services’ written child welfare investigations. These investigations are conducted and documented by social workers at social welfare offices, and the investigations sometimes have a major impact on the lives of individuals. The research material consists of 50 written child welfare investigations, social workers’ answers to interviews and questionnaires and also steering documents regulating the child welfare practice of the social services, but the study focuses on the written investigations. Drawing on genre analysis theory and critical discourse analysis, patterns of linguistic features in the investigations are highlighted and considered as genre-specific features. Overall the investigations as written documents are considered both as discursive tools in a professional setting and as social authorities’ texts with great power in an asymmetrical power relation between authorities and individuals. This inherent duality implies different communicative purposes which are difficult to merge in the same document. The study includes a variety of empirical data and analytical tools deriving from genre analysis, critical discourse analysis, corpus linguistics and linguistic stylistics. In the study both quantitative and qualitative approaches are combined, creating methodological triangulation. The results show that all the investigations are alike in terms of communicative purposes, indicating that the concept of genre is rigid concerning the text sample. In other respects all the investigations are characterized by variation, in both linguistic and more content-oriented aspects. In some sections of the texts the language is formal and in others it is casual. This can be understood as a consequence of different purposes coexisting in the same text. The results also show that different text participants are constructed differently concerning responsibility for affecting other participants. The authorities’ impact through processes is often hidden in passive clauses. Another result indicates that pseudo-nominalization is a functional linguistic tool in the discourse, which might be a reason to reevaluate plain language recommendations regarding this grammatical construct. / Texter med tyngd