Emergent verbal behavior in preschool children learning a second language.

We evaluated the emergence of untaught second-language skills following directly taught listener and intraverbal responses. Three preschool children were taught first-language (English) listener responses (e.g., "Point to the horse") and second-language (Welsh) intraverbal responses (e.g., "What is horse in Welsh?" [ceffyl]). After intervention, increases in untaught second-language tacts (e.g., "What is this in Welsh?" [ceffyl]) and listener responses (e.g., "Point to the ceffyl") were observed for all 3 participants.