This study tries to describe the noun plural system used by Hasidic adults living in Antwerp, Belgium, and to discover whether phonological regularities drive the choice of plural suffixation and stem shift, reckoning with various factors in the inflected singular form. Already extant Standard Yiddish suffixes emerge more frequently than those specific to Antwerp (loans from Dutch). The findings disclose a complex system of some powerful phonological regularities, subregularity islands and deviations that seem lexically ruled.