A research project investigated communicative language skills and the academic proficiency of native English speakers and limited-English-speaking (LEP) elementary school students. The subjects were 304 native English speakers and bilingual program participants, speakers of Lao and Spanish. The data are derived from a locally developed assessment system that has been validated. The results, based on analysis by language subsample, by grade and across grades, confirm that there are qualitative and quantitativce differences between the groups in all the investigated facets of English language proficiency. Meaningful intercorrelations among second language, school-based proficiencies are found in LEP students. A statistically significant association between receptive communicative proficiency and academic proficiency emerges for younger, but not older, native English speakers. A theoretical framework that captures the relationships among the stated proficiencies is found viable for both LEP and native English-speaking students. The implications of these findings for ESL and bilingual education programs are discussed. (Author/MSE)