The purpose of this study was to investigate twelfth grade writing instruction at one high school in the Northeastern Kentucky Appalachian region. At the time of the study, Kentucky schools were in a pivotal transitional period as they were adopting the Common Core State Standards while also removing the mandatory portfolio-based writing assessments that were a result of the 1990's Kentucky Education Reform Act. The study utilized both qualitative analysis and Systemic Functional Linguistics text analysis within a case study methodology to understand how writing was taught in the English Language Arts classroom at the school. Combining these two analytical frameworks allowed the researcher to bridge participants' understanding of the functions of language in writing instruction with concrete language resources that students used to both make meaning in their written texts and discuss their writing. The results of the analysis suggest that students and teachers had a shared metalanguage with which they discussed their understanding of language aspects of writing, but that this metalanguage was not functional in nature and was not connected concretely to the many different genres and rhetorical situations that students were asked to produce and consider. Several implications of the results are suggested, including that teachers and teacher educators need more explicit understanding of the value and praxis of using a functional metalanguage in their own pedagogy. [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.]