Heritage language acquisition has been characterized by various asymmetries, including the differential acquisition rates of various linguistic areas and the unbalanced acquisition of different categories within a single area. This paper examines Arabic heritage speakers' knowledge of subject-verb agreement versus noun-adjective agreement with the aim of contrasting their distributions and exploring areas of resilience and vulnerability within Arabic heritage speech and their theoretical implications. Two oral-production experiments were carried out, one involving two picture-description tasks, and another requiring an elicited narrative. The results of the study show that subject-verb agreement morphology is more maintained than noun-adjective morphology. Moreover, the unmarked singular masculine default is more robust than the other categories in both domains and is often over-generalized to other marked categories. The results thus confirm the existence of these asymmetries. We propose that these asymmetries may not be explained by a single factor, but by a complex set of morphological, syntactic, semantic, and frequency-related factors.