Studied were some cognitive aspects of the language development of a 2-year-old Puerto Rican boy who had been on the U.S. mainland 1 month. A Neo-Piagetian approach (developed by K. Witz and J. Easley) was used to study: language behavior as being embedded in more complex, unified systems; productivity of different structures and language patterns; and the increasing complexity of utterances. (LS)