Skinner’s revolutionary book Verbal Behavior

(1957) provides a taxonomy of seven verbal op-erants defined on the basis of their controlling variables. All of the verbal operants are established on the basis of the speaker’s direct contact with contingencies of reinforcement, which, with the exception of the mand relation, is always generalized conditioned reinforcement. Today a variety of language training curricula for learners with autism and other developmental disabilities are formulated on the basis of Skinner’s (1957) analysis of verbal behavior. The purpose of this commentary is to provide an overview of the role of reinforcement contingencies in the mand and tact relations, both of which are often made the focus of early language training efforts. We als