Analysis of data from the first six months of acquisition of English as a second language by a 5-year-old Japanese girl illustrates the role of modular “chunking” and coupling in the second language acquisition process. This process was apparent in the child's pre-copula and copula referential utterances. She produced a large number of creative and novel referential sentences by using a small number of patterns or modules. The same small set of patterns was seen in both adult and peer sessions, although advances in acquisition usually appeared in peer conversation before they were evident in adult session data.