Speech production involves the transformation of a to-be-expressed idea, or message, into lexical and grammatical content. Given the generally recognised separation of functional and positional processes, it has been argued that case assignment is within the domain of functional processes (or within Dell's syntactic stage). This article focuses on case assignment, which is achieved during the grammatical encoding stage of utterance planning. Early proposals for sentence production models were highly influenced by the distribution and characteristics of naturally occurring speech errors. More recent revisions of these models have been further influenced by experimental investigations into structural and word order alternations using a method called syntactic priming. This article first lays out in gross terms the general views of the stages necessary for sentence production. It then discusses the evidence that has supported the various stages of the production models and how they directly or indirectly inform us about the processes responsible for case assignment in sentence production. This includes evidence for and against (radical or weak) incrementality and evidence for lexical guidance (or verb primacy) in functional assignment.