This study had a two-fold purpose. It was concerned both with the effect of programed articulation therapy on Spanish-speaking subjects and with the role that distinctive features play on the phonological rules that affect articulation of three English phonemes. Fourteen adult Spanish-speaking subjects were involved and each demonstrated a functional misarticulation. Programed therapy proved to be a sufficient technique for improving misarticulation for two of the three phonemes. A comparison between the Spanish distinctive features and the English distinctive features proved that Spanish subjects substituted known Spanish distinctive features for unknown English distinctive features, thus explaining several misarticulations. These results are important to the therapist, for they point to an efficient therapy program and show that by looking at the underlying rules it is possible to gain a broader and more complete picture of what creates the misarticulations in each of the Spanish-speaking adults. (Author/JM)