The article is devoted to spelling errors of Russian learners in a French-speaking environment. Based on 1,816 spelling errors, the analysis focuses on four mechanisms (transposition, insertion, omission, and substitution), and the influence of contextual and non-contextual (cognitive, inter- and intralinguistic, extralinguistic) factors is taken into account for each mechanism in question. Despite the multidimensional nature of the factors involved, the recurrence of certain errors makes it possible to distinguish clear trends in the acquisition of linguistic facts. In addition, a quantitative analysis of the obtained data allows cross-sectional studies of errors, which traces back the steps in the acquisition of various aspects of Russian spelling, from A1 to C1 level for the first time. Moreover, the qualitative analysis of errors provides valuable data for pedagogical materials.