Since the advent of the internet, its daily user base has increased significantly. Writing blogs and comments became more and more common, and as a result the language of the internet began to develop. While reading records on the internet, in addition to interesting modern language, we also find language errors that users are often unaware of. The Polish and French online comments are analyzed in the master's thesis. The master's thesis consists of two parts. The first part presents the theory where language errors, innovations, and other categories are described. The second part of the master's thesis is empirical. The empirical part is based on the linguistic analysis of selected Polish and French comments and a tabular presentation of the frequency of each category. At the end of the master's thesis, the statistical data of the linguistic analysis is presented.