This paper considers the well-known puzzling phenomenon of subjectverb agreement asymmetry in Arabic: full agreement surfaces in SV word order, whereas VS order manifests partial agreement. That is, agreement in all phifeatures surfaces only when the subject moves to a preverbal position. To avoid (apparently inevitable) circularity of earlier analyses, the paper offers a minimalist, phase-based analysis to the phenomenon. Two ingredients to the analysis are proposed: phase sliding, according to which a phase extends if its phase head moves. More precisely, T becomes a (sort of) phase head when after v-T movement. The other element is a morphological rule, Morphological Agreement Realization (MAR), to the effect that morphological agreement surfaces iff the probe and goal are spelled out in the same phase. Thus, it turns out that in VS word order, the subject and the verb are spelled out in different phases. In SV constructions, on the other hand, both the subject and the verb are spelled out in the same phase. Hence, the agreement asymmetry. The analysis is supported by certain phonological phenomena.