The purpose of this study was to examine the differences in the academic growth in mathematics and reading for elementary Spanish-speaking English language learners, in relation to teacher certification and training in teaching English as a second language (ESL). The study was conducted in a Midwestern urban public elementary charter school. A quasi-experimental research design was used with a sample size of 3,285 student scores in the control group and 423 student scores in the treatment group. Data were compiled from the fall of the 2017-2018 school year through the winter of the 2021-2022 school year and then a two-sample t-test was applied to compare the mean growth scores of the two groups. As a comparison point, the Northwest Evaluation Association (NWEA) was used in this Midwestern district as a measure among all students. The results demonstrated that student scores when receiving instruction from an elementary teacher licensed in ESL showed growth as compared to those who received instruction from a teacher without the ESL licensure. There was no statistical significance when analyzing the growth measures when broken down by the content areas of reading and mathematics. As numbers of English learners increase across the state, the intent of this study was to demonstrate potential benefits in employing teachers with ESL licensure in elementary classrooms. [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.]