The representation of word boundaries constitutes a central issue of many writing systems and orthographies, especially when two different components of a segmental phonographic and a word-based morpho-syntactical principle interact. This interaction will be studied in the context of literacy transfer from a L2 learnt at school to a vernacular and non-written L1. The central question of this paper will be how three different types of literate and metalinguistic knowledge intervene in this process. As a case study, the spontaneously written narratives of Moroccan school children who speak Tarifit Berber as their first language in Germany (with German as L2) and Morocco (with Modern Standard Arabic as L2) will be analysed. It is assumed that the writing of Berber in these two settings does not only differ on the level of the two different scripts, but also on the level of very divergent orthographic principles at the morpho-syntactical level. This paper presents material from two research projects on literacy acquisition of Moroccan students in Germany and Morocco, in which students from different grades were asked to produce oral narratives in Berber (and their second language, i.e. Arabic or German, respectively) and then to transcribe them according to their preferred script system. The similarities in the treatment of word boundaries cut across the overt differences in the choice of the script system: pupils in Germany, even if they use the Arabic script, transfer a word concept from German, while in Morocco, even in the case of Latin letters, a different model is dominant. As will be shown with respect to the problem of prepositional phrases in detail, the different models function like “matrix scripts”. They indicate at the same time, albeit in different degrees, a cultural accommodation to the dominant school or official language.