This study is about the occurrence of code-switching, language alternation, in intercomprehension, a plurilingual context. In this approach for the learning/teaching of languages, predominantly from the same family, the learners communicate mainly in their native language and develop skills in understanding the other languages involved and in making themselves understood. In foreign language teaching, the phenomenon of language alternation is still often regarded as "interference" of the learner's mother tongue, although there is a growing tendency to accept it as a pedagogical tool. The aim of this research is to investigate the importance of code-switching for intercomprehension, in the socio-pragmatic and pedagogical perspectives. Theoretical-analytical parameters were established from the main functional typologies created by researchers in the socio-pragmatic and pedagogical studies of code-switching, from the conversational approaches by Peter Auer and from Ethnomethodological Conversation Analysis. The analysis of interactions between participants of the Galanet online platform, a Romance languages intercomprehension project, is carried out to examine how code-switching appears in the project, how it can contribute to the linguistic and cultural exchange, and how it can be used in a teaching/learning proposal. This study intends to contribute to the research in plurilingualism and intercomprehension, which currently focuses on teacher training, curricular insertion, the improvement of ongoing projects and the development of new projects.