This paper is concerned with the grammar of cognate constructions, which are defined as those in which the object and verb have the same meaning ("I drank a drink of water"). In the transformational process of dissimilation the verb is replaced by "have" or "do," so that verb and object are less alike. The model used i" the case grammar of C.J. Fillmore ("The Case for Case" ED 019 631). Types of English cognate constructions are examined in detail. The conclusion is reached that context-bound meaning is the property that distinguishes dissimilative pro-verb behavior from main-verb behavior. Specific verbs when used as pro-verbs lose their grammatical-semantic features and become configurational function words which take their meaning from the constituents in their sentential frame. (KL)