The development of double negation in Arabic has attracted increasing attention in recent years (Lucas & Lash 2010; Wilmsen 2014; Diem 2014). The striking parallels between negation in Berber and North African Arabic invite an explanation in contact terms, and such explanations have indeed been proposed (Lucas 2010; Lucas 2013) and disputed (Brugnatelli 2014). However, in addition to serving as a postverbal negative, reflexes of šayʔ have a number of other functions across North African dialects not directly related to negation, notably indefinite quantification and polar question marking. The marking of these functions, too, shows striking Arabic-Berber parallels generally neglected in discussions of the phenomenon, and absent even from Kossmann’s (2013) comprehensive overview of contact effects on Berber. Taking these into account produces a more complete picture of Arabic influence on Berber, and provides clues to the relative chronology of the developments in question in both. As in other cases, it appears that Arabic influence on non-Arabic varieties sometimes preserves usages obsolete in present-day regional Arabic dialects.