English learners are one of the fasting growing populations of students in the United States, particularly in the Southeast. Little is known about how teachers in this region support the instructional needs of English learners in a mainstream classroom, despite reports that they receive limited preparation and professional development to meet the unique needs of those students. The purpose of this dissertation study was to explore and analyze the scaffolding practices of four mainstream teachers of English learners. The following main research question guided this investigation: How do mainstream teachers scaffold instruction for English learners in a Southeastern elementary school with a high growth rate of English learners? This study also analyzed three sub-questions: a) What types of instructional practices do mainstream teachers use with English learners? b) What types of professional knowledge about second language acquisition do mainstream teachers demonstrate in their scaffolding practices? and c) What personal attitudes and beliefs do mainstream teachers have toward language diversity and second language instruction that influence their scaffolding practices? This study utilized a qualitative, multiple case study design, employing data sources in the form of survey instruments, interviews, and classroom observations. Data was analyzed by highlighting the findings, identifying the patterned regularities, and constant comparison of data. Three themes were identified, as well as one major finding. Teachers in this study scaffold instruction for ELs through three types of instructional scaffolding: bridging, contextualization, and building schema. Improving the quality of professional knowledge about second language acquisition and transforming beliefs about ELs and second language instruction to improve the quality of instructional scaffolding were other themes that emerged from the data. Collaboration with the ESOL teacher was beneficial in helping teachers scaffold instruction for ELs. Future research studies should investigate high-quality professional development programs for in-service teachers and successful collaborations between mainstream teachers and ESOL teachers. [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/en-US/products/dissertations/individuals.shtml.]