ABSTRACT This paper provides a detailed morphosyntactic analysis of modals in Jordanian Arabic (JA henceforth). It is mainly concerned with delineating the categorical status of JA modals. The paper defends an alternative perspective of the conventional ‘auxiliary, verbal, pseudo-verb and particle’ view of the morphosyntactic categorization of modals in Arabic in general and in JA in particular. It is proposed therefore that JA modals laazim ’must’ and mumkin/yemkin ‘may/might’  belong to an ‘open/null category’ and the modal bighdar ‘can/could’ belongs to a ‘quasi-auxiliary’ category and not to any of the conventional categories of auxiliary, verbs, pseudo-verbs and particles that are assumed in the literature. Furthermore, the paper shows that JA modals exhibit inconsistent and non-coherent morphosyntactic behavior. Based on this fact, it is concluded that JA modals form quite heterogeneous rather than homogenous group. Crosslinguistically, the heterogeneity and the proposed open/null category of JA modals lend further evidence to the difficulty to universally define the category of modals on formal grounds (Machova2015).