This study examines linguistic form and communication style in working-class and middle-class black preachers of two types: those who are not seminary trained, who preach spontaneously, and those who are seminary trained, who read from a prepared text. Ten sermons were tape-recorded in natural settings at two churches in Washington, D.C. Analyses indicated that working-class, untrained preachers manipulated a wider and more-consistent range of linguistic and nonlinguistic variation, in which both standard and nonstandard features strategically interacted. This variable use of standard and nonstandard expression was sensitive to questions of social function and social meaning. The study also analyzes differential use of rhetorical devices that (1) elicit and guarantee the active participation of the audience and (2) serve to enhance the effectiveness of sermons. Qualitatively different communication styles characterize both seminary-trained and untrained preachers. (Author/AA)