The Split Intransitivity Hierarchy (SIH) proposed by Sorace (2000) is an aspectually gradient classification of unaccusative and unergative verbs. This hierarchy has been attested in many Western European languages. However, little is known about typologically different languages. This dissertation provides an account of the gradience in aspectual and thematic specification of intransitives in Modern Standard Arabic (MSA). It seeks to confirm whether the SIH exists in Arabic and whether it applies to its syntactic characteristics of split intransitivity. Following Sorace’s classifications, Arabic intransitives are divided into seven categories: change of location, change of state, continuation of a pre-existing state, existence of state, uncontrolled process, controlled motional process, and controlled nonmotional process. To test the behavior of these verb classes, the researcher applies diagnostics of split intransitivity and carries out tests of telicity, stativity, and durativity. In addition, the researcher examines the contribution of the outer/grammatical aspect to the inner/lexical aspectual specification of the verb in MSA. Native speakers’ judgment is utilized to distinguish grammatical examples from ungrammatical ones. The results confirm the existence of the SIH in Arabic. Arabic intransitives are subject to systematic variation in their lexical aspect as they show different degrees of telicity and durativity. Specifically, verbs of change of location show core unaccusative/telic behavior, while verbs of change of state oscillate in their telicity. Verbs in the middle of the hierarchy are the most indeterminate about their aspectual and thematic realization. The findings also reveal that Arabic verbs of continuation are durative, while verbs of existence are mostly stative. Moreover, durative classes in Arabic show variable degrees of durativity. In particular, the class of uncontrolled process displays the lowest degree of durativity. Verbs of controlled motional process are more unergative/durative than verbs of uncontrolled process and less categorical in their behavior than verbs of controlled nonmotional process. Finally, verbs that denote controlled nonmotional processes are core unergative/durative and the most unambiguous in their behavior. Overall, Arabic intransitives keep their original aspectual classification even when changing the outer aspect from perfective to imperfective.