In this paper, the unexpected behavior of object negative quantifiers in some diagnostic tests of sentential negation is accounted for within a Minimalist framework assuming that: (i) negative quantifiers decompose into negation and an existential quantifier; (ii) negative quantifiers are multidominant phrase markers, as Parallel Merge allows the verb to c-select their existential part but not their negative part, thus giving negation remerge flexibility; (iii) tag questions involve or-coordination of TPs, and neither/so clauses involve and-coordination of TPs; (iv) two positions for sentential negation are available in English, one below TP (PolP2), and one above TP (PolP1). Activation of either PolP1 or PolP2 in the absence of other scope-taking operators corresponds to two distinct grammars. If PolP1 is active, the negative part of an object negative quantifier remerges in its Specifier valuing the [upol: ] feature of Pol1 as negative ([upol:neg]) while skipping the TP-domain. As no negative formal feature is present in the TP, a negative question tag is required, as well as so-coordination, too-licensing and Yes, I guess so ‘expression of agreement’. Conversely, if PolP2 is active, the negative part of the object negative quantifier remerges in the TP-domain (in Spec, PolP2), thus requiring a positive question tag, neither-coordination, either-licensing, and No, I guess not.

This study investigates the areas of resilience and vulnerability in sentential negation in heritage Egyptian Arabic and explores their theoretical implications. Egyptian heritage speakers completed three narrative production tasks, five experimental production tasks, and a acceptability judgment task. The results indicate that they have a full grasp of the location of negation and its configurational properties, but diverge from native speakers in such aspects of sentential negation as merger with lexical heads and dependency or licensing relations. We propose that these asymmetric patterns are due to various factors, including the age at which a structure is typically acquired in the L1, as well as its morphological and syntactic characteristics. The results of this study have implications for the ongoing debate in heritage language research about the linguistic areas that display greater stability/vulnerability. For example, phrase structure seems less vulnerable than licensing dependencies and the mapping between syntax and the morphological interface.