9 are termed Cuban-Americans. They represent the group of Cuban im migrants who arrived in the .S. prior to the 1980 "Freedom Flotilla" or "Marie! Boat!ift." Justification The second language research by Rodriguez-Brown (1979), who looked at primary Mexican students in Chicago, along with the work of Cummins (1981), Cummins, Swain, Nakajima, Handscombe, and Green (1981), and Cummins, Swain, Nakajima, Handscombe, Green, and Tran (in press), who looked at the relationship of first and second languages across ages, indicates that first language proficiency is related to second language acquisition. Cummins et al. (in press) point out that the theoretical assumption of "common underlying proficiency" is a construct which "... appears counterintuitive to many policy makers and educators" (p. 2). Cummins et al. (in press) state that research in behavioral and language use patterns across languages is an innova tion in second language study that requires a great deal of further investigation. The controversy regarding the use of primary language instruction to enhance second language learning has continued for the past decade, yet most second language research has been focused on elementary school students and adults learning a second language (Hatch, 1978). Hatch documents that between 1913 and 1976, 75 second language acquisition studies of children 12 years or younger were conducted. During the same time period, 30 studies of adults and 11 studies of teenagers also occurred. Both Genesee (1978) and Snow and Hoefnagel-Hohle (1978) agree that adolescents learn the rule-governed parts of language--those aspects