Abstract
English Language Learners (ELLs) are often deprived of using English for academic purposes in meaningful and authentic contexts when pulled out of the classroom for English Language Development services. To tackle this issue, schools have increasingly integrated ELLs in the mainstream classroom through an inclusive model of co-teaching between one content and one language teacher. Through a case study approach, we explored two co-teachers' practices that fostered writing development within one first grade linguistically diverse mainstream classroom. Through analysis of classroom interaction as well as teachers' and researchers' notes, findings revealed that in holding core shared practices, the two teachers achieved an enhanced ability to scaffold their teaching to support their students' writing development. Core shared practices included a sensitive view of students' academic language and writing development, modeling for conversations about writing, embedding specific scaffolds for academic language, and opportunities for talking and sharing ideas about writing. These core practices enabled the ESOL and content teacher to take up and share equal and complementing roles during planning, instruction, and assessment. Co-teaching can yield positive results provided that the ESOL teacher has a central, not peripheral role in the mainstream classroom.