The demographic landscape of foreign language courses in the United States, specifically Spanish, is constantly changing. College professors and 9-12 Spanish instructors are facing a unique situation: teaching traditional Second Language students (SLs) and Heritage Language Learners (HLLs). This literature review focuses on how the shifting emphasis of language skills (speaking, listening, reading, and writing) in 9-12 instruction and university-level instruction shapes the academic and affective learning experiences of both HLLs and SLs. Historically, K-12 curricula have claimed to focus on a communicative approach, prioritizing verbal skills; however, institutional constraints force instruction to focus on certain aspects of language, such as grammar and preparation for standardized tests. This creates an environment that rewards memorization among SLs and forces HLLs to submit to a type of Spanish that is unfamiliar to them, penalizing the implicit, natural fluency they have and stigmatizing regional dialects. Conversely, university-level Spanish courses possess the curricular autonomy to implement specialized heritage tracks that explicitly target "frontstage" academic literacy as well as the development of other language skills to bridge the HLL literacy gap. This structural divergence impacts sociolinguistic attitudes within SLs and HLLs due to standard textbook-driven 9-12 instruction conditioning heritage and non-heritage students to internalize rigid dialectal hierarchies that persist into the university level. Ultimately, this review highlights the critical need for a more cohesive articulation between secondary and higher education language curricula to foster a more equitable, validating, educational, and communicatively effective learning environment.