A rationale for language intervention is outlined according to two basic dimensions (increased output and knowledge of language) and their respective strategies (operant procedures and a psycholinguistic model). Thus, behavior modification and transformational grammar are viewed as complementary for an efficient language intervention program. The following basic language intervention needs are delineated: first language learning, second language learning, intermodality transfer, and language rehabilitation. Also, the following ten intervention techniques are presented: correction, expansion, expatiation (simple), expatiation (complex), alternative, completion, replacement, alternative-replacement, combination, and revision. Moreover, the rationale calls for the incorporation of the following principles: informality, active participation, no premium for correctness, variety of stimulation and responses, and peer competition in appreciating intuitive knowledge of language. (Author)