Theta roles (hereafter θ-roles) are the semantic roles borne by noun phrases in a sentence that designate ‘agent of action’, ‘patient of action’, and so forth. As such, they constitute an essential part of a sentence's semantic interpretation. The concept, though not the name, is used in the beginnings of Arabic grammatical study. Saad (1982:87) observes that the medieval grammarians classified sentence elements semantically, for example as fiʿl ‘action’, fāʿil ‘actor’, and mafʿūl ‘acted upon’. Comparable designations pervade Wright's (1974) grammar of Classical Ara…