In this article we discuss a contrastive, morphological agreement pattern exhibited by singular possessive pronouns in West Flemish and German. While West Flemish zen (‘his’) and eur (‘her’) require a suffix -en to mark masculine agreement, they are unmarked for feminine agreement. Conversely, German sein (‘his’) and ihr (‘her’) require a suffix -e to mark feminine agreement, but they are unmarked for masculine agreement. Put differently, in both languages only one gender is marked for agreement, and West Flemish marks a different gender than German. To account for this intra- and cross-linguistic variation, we argue for a fine-grained analysis, couched in Nanosyntax (Starke 2009 et seq.), of the possessive pronouns and their agreement markers.