In this paper, we focus on partitive articles (PAs), i.e., determiners which, generally, have an indefinite interpretation, and on one of their potential correlates, i.e., invariable de, in Francoprovençal, a non-standardized, highly endangered Gallo-Romance language (cf. Zulato, Kasstan & Nagy 2018), and show the fine-grained spatial distribution of these elements in the Swiss and Aosta Valley (Italy) varieties. Presenting several maps based on fieldwork data from Valais (Switzerland) and the Aosta Valley (Italy), we demonstrate that the spatial distribution of PAs and de is more complex than reported in the literature: we complement the basic subdivision of Francoprovençal into two types, Francoprovençal A and B (cf. Kristol 2014, 2016), with a more nuanced picture, in which the morphosyntactic features of PAs play a crucial role: in Francoprovençal A, the presence of PAs depends on the syntactic context whereas, in Francoprovençal B, their presence is limited mainly to two areas, in which singular and plural PAs do not occur together (one area only has singular PAs whereas the other one only has plural PAs). We also show that there is no correlation between phonologically overt plural marking on nouns and absence of PAs; however, we found a correlation between overt sigmatic number marking on nouns and absence of PAs.