Foreign language learners are considered orthographically competent when their texts are free from orthographic errors (vgl. GER 2001: 118). This claim is noteworthy with regard to comma placement as part of orthographic competence, considering that comma placement of native writers of German is far from being error free. Their comma errors are supposed to be connected with implicitly acquired strategies that build on lexical, prosodic and semantic features of text, but are rarely motivated syntactically - in contrast to the norm and system of German comma placement. It is yet unexplained in how far such other motives than syntactic ones have also an effect on comma placement of foreign language learners and what role interferences with their first languages play. My article follows this lack by presenting an exemplary analysis of comma errors in free texts made by advanced learners of German as foreign language with Italian as their first language. In my investigation I consider contrastive differences between the German and Italian comma system as well as the observed implicit comma strategies of native speakers as potential reasons for errors. The results indicate that the few errors made by the participants can be mainly explained in an interlingual way.