Teachers need support with on-going professional learning to effectively address Spanish-speaking biliterate students' strengths and language needs. They also need to build capacity in learning new standards and in implementing policy. This study utilized Communities of Practice and Latina/o Critical Race Theory to explore the learning process of four elementary school teachers. Data included field notes teachers' written reflections, audio recordings of multiple elements of this professional development, and pre/post teacher interviews. Data were analyzed using memos and cycles of coding. Findings demonstrate that teachers' understanding of new standards and language policy grew and their philosophies and practices shifted. These changes took place as they developed a close community, discussed language instruction as it intersects with issues of social justice and equity, and practiced new strategies based on their students' strengths and needs. Findings showed that learning and implementation of instructional practices occur with three conditions: collegial community, practical resources, and invested domain. A critical discovery was the importance of confianza (mutual trust and care). With confianza, teachers shared with ease, supported and challenged one another, and engaged in social justice and equity conversations. Recommendations to school leaders designing professional development are to establish trust, give teachers voice in choosing their focus of study, provide resources, and integrate social justice and equity discussions. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]