The Traditional Arab Grammarians (TAGs) (Sībawayhi 8th century) assigned somewhat similar terminology for the inflectional states of Standard Arabic (SA) verbs and nouns. Verbs could be either marfūʕ ‘Indicative’, manṣūb ‘Subjunctive’, majzūm ‘Jussive’, or mabnī ‘uninflected for mood’, making reference to so-called ‘mood’ endings. Likewise, nouns could be either marfūʕ ‘Nominative’, manṣūb ‘Accusative’, majrūr ‘Genitive’, or mabnī ‘uninflected for case’, making reference to case endings. Thus, TAGs named Ind-marked verbs and Nom-marked nouns marfūʕ, and Sub-marked verbs and Acc-marked nouns manṣūb, in reference to the morphological similarity between the relevant nominal and verbal suffixes. Nonetheless, this similarity is observed between 10 out of the 14 sets of verbal and nominal suffixes in the Ind-Nom paradigm, and between only 4 out of the 14 sets of verbal and nominal suffixes in the Sub-Acc paradigm. In other words, the presumed morphological similarity in terms of suffixes is not perfect. Therefore, this paper aims to show that, at some stage in word formation, the two sets of verbal suffixes, indicative and subjunctive, are identical to the two sets of nominal suffixes, Nom and Acc, respectively, for the verbs and nouns that encode the same number and gender features. After that stage, verbal forms undergo certain word formation operations (feature movement and feature deletion) that affect their structure, resulting in the known surface forms. This account is based on a novel analysis of the SA imperfective paradigm. Both accounts will be presented in purely descriptive terms, without making reference to any available morphological framework.