This research studies the cognitive processes implemented during the production of explanatory text in L2 language in the Algerian plurilingual context. The apprentice writer of explanatory texts has difficulty producing written material in a language that is not his mother tongue (L1). The use of verbal interactions between pairs is an aid that facilitates the planning activity, the activation of linguistic and thematic knowledge and the activity of putting into words. The verbal exchanges between peers allow in fact, an optimal activation of the previous knowledge of the participants, of the students of the CEIL of the ENS of Bouzaréah. These exchanges reduce the cognitive burden associated with the activation of this knowledge, facilitate the provision of resources memoranda needed to manage the process of putting into words that present particular difficulties for the text writers in L2 language. Analysis of the results obtained in this research indicates that verbal interactions between pairs play a decisive role in the activation of planning and word-writing processes and help writers to activate two types of knowledge the writing activity: knowledge of the language and knowledge of the world domain referred to in the text. These interactions allow learners to produce better quality explanatory texts at the textual surface and semantic content level. Results that highlight the important role of interactions in the construction of written production skills in the L2 language in a plurilingual context open up new perspectives in the development of new literacies in plurilingual and pluricultural contexts.