This dissertation considers whether the Koine Greek dialect variations in the New Testament books of Luke and Acts may be attributed, in part, to the writer's selection of different registers to suit each topic, providing greater amounts of Semitic linguistic phenomena in connection with Jewish subject matter while employing standard Koine in sections with Hellenistic themes. It will be shown that the modulations of Semitic influence throughout these two books reflect a multilingualism that was widespread in the first century Mediterranean world, and that the author's use of a continuum of Semitized Greek functioned quite like the metaphoric code-switching of modern bilinguals, vividly evoking the original events for his readers. (Disseration Abstracts)