The major hypothesis of this study is that a significant relationship exists between English language ability (as measured by the Illinois Test of Psycholinguistic Abilities (ITPA) Full-Scale score) and language-modeling by the mother (as measured by the Mother-Child Interaction score on the Language Model Matrix), and between English language ability and total home language-modeling (as measured by the Total Interaction score on the Language Model Matrix). Sub-hypotheses state that English language ability, language-modeling by the mother, and total home language-modeling significantly differ according to (1) ethnicity, (2) socioeconomic status (SES), and (3) language model type. The sample consisted of first-grade children: 50 Navajo Indian, 55 Pueblo Indian, and 50 rural Spanish-American. A Language Model Matrix was designed to provide an operational framework. Test results support the major and sub-hypotheses. As acculturation and SES increase, so does the quantity of verbal interaction in the home. Programs to alleviate poverty, and to teach mothers how to teach their children, are of vital importance in the elimination of linguistic disadvantagement. (Author/NH)