The purpose of this study was to determine the perceptual language and academic achievement functions of English, Spanish, and Navajo children experiencing learning problems and referred for placement into special education classes. Those test variables which discriminated among the native English-speaking children and the children who spoke Spanish or Navajo natively were, as predicted, those tasks which involved knowledge of the linguistic rules of English. It would seem that, taken as a group, the school learning problems experienced by the native Spanish- or Navajo-speaking children were the result of their limited linguistic competence in English, the language of instruction in their classrooms.