This mixed methods study examined the language development support provided to English Language Learners in the Math classroom. The research questions explored the knowledge and motivation of Math teachers and the organizational influences at the school that impacted the teachers' ability to demonstrate competency in supporting language development appropriately in the Math classroom given the unique language proficiency needs of students and the demands of the mathematical content. The Clark and Estes Gap Analysis Framework (2008) was utilized and the organization of the study related to the assumed knowledge, motivation and organizational influences. As teachers described their instruction and support for students learning English, gaps were revealed as related to their factual and metacognitive knowledge that allowed them to specifically address language demands that aligned with the Math content as well as the individual language development of students. While the teachers recognized the benefit and importance of practices to support language development in the Math classroom, there was a motivational gap pertaining to self- efficacy and attribute theory. A majority of teachers did not express confidence in their ability to support students learning English nor did they attribute student achievement or lack thereof to primarily instruction. Administrators were also surveyed and interviewed as a means of strengthening the data gathered on the organizational influences. Administrators expressed similar knowledge and motivation barriers. The teachers perceived the organization as not explicitly addressing the needs of English Language Learners especially considering the experience of ELLs in Math. This was evidenced through a lack of training, best practices, feedback and organizational support for initiatives to support teacher knowledge of developing language in all content areas (Math included). The results and findings suggest that additional training is needed that includes modeling and opportunity for reflection and feedback that increases teacher knowledge and motivation about supporting ELLs in Math. The training and opportunities for feedback should include opportunities for explicit modeling of instruction that specifically targets the language proficiency of students as well as addresses the rigor of grade level Math content in a way that is developmentally appropriate. The results and findings from the research provided a framework for developing a recommended training program based on the New World Kirkpatrick Model (Kirkpatrick & Kirkpatrick, 2016). This training program addresses the knowledge and motivation gaps aiding in the realization of the stakeholder and organizational performance goals. [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.]