This study examines the language use patterns of students in a math class that is part of a Spanish-English two-way, secondary continuation program. Audio recordings from five class periods were analyzed in order to quantify the opportunities provided for minority language by the teacher, as well as student uptake of those opportunities. This is the first known study to quantify both opportunities and uptake. Additionally, the language use patterns of four focal students were explored. These four students represent the three most common linguistic profiles of DLI students: Spanish home language, English home language, and new-to-the-country. Finally, evidence of motivation and willingness to communicate were described in partial explanation of the language patterns of these four students. Findings indicate that students were given few opportunities for sustained minority language use and student uptake patterns generally reflected this. Additionally, the DLI students in this study tended to use more English than Spanish in the classroom, while the newcomer student spoke almost exclusively in Spanish. Motivation and willingness to communicate were shown to play a significant role in students' language use patterns. Findings support the need for modifications to the L2 Motivational Self System (L2 MSS) when analyzing the motivation of balanced bilinguals. Pedagogical implications of the study point to a need for activities and interventions that provide increased opportunities for sustained minority language use. Increasing the opportunities for sustained minority language use and sustained uptake of these opportunities are crucial steps in helping secondary DLI programs maintain fidelity to the DLI model and to helping students achieve high levels of bilingualism and biliteracy (CAL, 2016). [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]