The purpose of this case study was to evaluate to what extent individual teachers in a small, rural high school have the capacity and pedagogical skills to teach non-English speaking individuals within a sociocultural theoretical framework. Using a mixed methods approach, this case study measured teacher efficacy and their use of best practices for English language learners using an adapted teacher efficacy scale (Tschannen-Moran & Hoy, 2001), Sheltered Instruction Observation Protocol (Echevarria, Vogt & Short, 2000; 2004; 2008; 2013; 2017), achievement data, and a semi-structured interview. This study confirmed the need for teacher professional development that focuses on best practices for working with English language learners to support and positively expand the attitudes and beliefs on the part of educators. Also, that there is a potential for this study to become a framework for evaluating the efficacy of an ELL program when ELLs are receiving instruction in mainstream classrooms. [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.]