This study evaluated a behavioral teaching strategy for teaching the use of compound predicates in writing to three academically deficient, behaviorally disordered boys (ages 9 to 13). The strategy attempted to affect the number of compound predicates per T-unit (minimal terminable unit) per 20-minute writing session using a combination of sentence-combining exercises and reinforcement. The three students showed systematic increases in the number of compound predicates they wrote during each writing session. Results suggest the usefulness of the T-unit as both an instructional unit and for research purposes. (15 references) (DB)