Studied the development of speech act comprehension in 36 retarded and 36 nonretarded children at the developmental ages of five, seven, and nine years. Retarded and nonretarded individuals followed the answer obviousness rule and used the contextual and linguistic clues available to respond to yes-no interrogative sentences. (RJC)

Samples of the communicative behavior of a group of mildly mentally retarded adults were examined for indications of mature linguistic competence (specifically, grammatical morpheme and complex sentence use).Findings confirmed the expectation that the eventual mastery of these aspects of linguistic competence in higher-level retarded individuals…