The article analyzes the use of code-switching for interaction management between an Italian native language teacher and students whose native language is Brazilian Portuguese and, in some cases, Italian, during a Cycle of seminars aimed at the elaboration of a scientific article in Italian foreign language. From the analysis it emerges that, since it is a linguistic context between bilingualism and exolingualism, the use of code-switching is sporadic, when it is present it triggers the activation of sequences of "natural pedagogy" directed to the one who holds a greater linguistic competence to fill lexical and stylistic gaps that the writing phase favors. The occurrence of a code other than Italian can also lead to problems of understanding in the presence of words of which the meaning is not known, in which case it is observed that speakers put in place a series of joint discourse modes that range from reformulations and exemplifications to translation and code-switching to Portuguese, used to solve the communicative problem. It is concluded that in the interaction of high-level students confronting academic writing, code-switching helps to create the conditions for the co-construction of declarative and procedural knowledge relating to the writing of an article, in which context the different actors (teacher and students) contribute by providing their own specific skills