A 1973 study of 341 Mexican American nonmetropolitan high school sophomores in South Texas and 300 Mexican American sophomores and seniors in El Paso high schools and a 1978-79 replication study of 89 metropolitan and 65 nonmetropolitan Mexican American youth explored the difference in their Spanish-English language usage patterns. Both studies indicated that nonmetro youth used Spanish more often with families than did metro youth. However, findings from the two sets of comparisons were in direct conflict in terms of relative predominance of Spanish in all other interaction contexts. The 1973 study indicated that metro and nonmetro youth differed little in their use of Spanish versus English language mass media; the 1978-79 study indicated that, although metro and nonmetro youth did not differ in use of Spanish language radio programs, the nonmetro respondents' use of Spanish reading materials and television was less. The 1973 study indicated that nonmetro boys tended to retain predominant use of Spanish outside of interaction with parents while others did not. The 1978-79 study indicated that both metro and nonmetro girls spoke more English with family and friends than did boys. (CM)