The purpose of this comparative study is to determine whether the linguistic input approach based on Krashen's (1989) comprehensible input (CI) and supported by Kolb's (2015) experiential learning (ELT) and Siemens' (2005) connectivism theory (CT) to improve eighth graders' Spanish speaking and writing linguistic proficiencies. Previous research on world language acquisition demonstrated that Krashen's (1989) Input Hypothesis (IH) approach can further students' linguistic proficiency. However, eighth graders have a fixed time to achieve their needed linguistic goals within a school year to be promoted to their preferred world language levels in high school, where they may require an approach that covers both Spanish linguistic fluency and grammatical accuracy. Therefore, this comparative study examined how eighth-graders linguistic fluency improved through a CI approach curriculum versus a curriculum that followed a grammar methodology. The intervention took place in an academic setting in San Diego, California. The intervention compared students' results from four cohorts, two being the control groups and two being the experimental groups. Two of the cohorts' participants (C, CD) had at least 1 year of experience learning Spanish as a world language, and the other two cohorts' participants (A, AB) had at least 3 years of experience learning Spanish as a world language. [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.]