Low topics are not IP-external: a reply to Alzayid (2025)

This article defends the hypothesis that right-dislocated elements in Najdi Arabic (NA) are IP-internal low topics, contra Alzayid's (2025) recent claims of their IP-external status (Alzayid, Ali. 2025. On low topics in Najdi Arabic: A rejoinder to Alshamari and Jarrah (2022). Linguistics 63.6). Through a critical evaluation of Alzayid’s three empirical arguments – centred on NPI licensing, subject-verb agreement in VOS configurations, and wh-focus interactions – this reply demonstrates that his conclusions rest on misinterpreted diagnostics or theoretically untenable assumptions. Drawing on the cartographic tradition and phase theory, I argue that right-dislocated constituents exhibiting clitic doubling and definiteness effects are best analysed as merged within the low periphery, between TP and vP. The Agree relations between T and the low subject remain intact without invoking pretheoretical machinery or IP-external adjunction. Moreover, I show that NPI behaviour reflects semantic indefiniteness rather than syntactic height. This analysis reinforces the view that discourse-related material in Arabic clause structure can occupy structurally encoded low positions, thus supporting a richly articulated left and low periphery.