Role play with toys was modeled to develop communicative language function in 14 visually impaired Ss (ages 8-26 years) who also were mentally retarded. Before treatment, Ss' language was non-communicating and characterized by echolalic and stereotypic verbal responses. Few questions and little narrative speech was present even in those Ss who had fully developed sentence structure. Among the findings was that the Ss acquired dialogue behavior as they learned to role-play. Communicative function was established with shared referents (play themes and toy props) and cooperative social routines (role play). Play themes which were of personal interest elicited the greatest participation. Nonverbal Ss did not develop symbolic play, but did establish communicative responses as they began to anticipate and express preference. No change was noted in the level of syntax or vocabulary development in verbal Ss. Verbal expression increased and narrative and question forms appeared. Language behavior became more communicative and meaningful as social interaction increased. (Author/DLS)