This research study was based on Vygotsky's learning theory, the Zone of Proximal Development (ZPD). The Think Aloud strategy provides an effective scaffolding technique that is advocated in Vygotsky's conceptualization of ZPD. This study examined the effect of the think-aloud instructional strategy using academic language and problem-solving thought process on English Language Learners' student performance with solving word problems when teachers implement the protocol in middle school mathematics classrooms. This empirical study utilized a quantitative single-case research design for data collection and data analysis. The data collection occurred during the concurrent learning model due to the COVID-19 pandemic. In the single-case research study, the data were analyzed using the multiple baseline design composed of a baseline without think-aloud and treatment with the think-aloud strategy. The multiple baselines revealed seven trends, including task performance, academic language usage, a proportional relationship between task performance and academic language usage, gender differences, speaking vs. writing, the complexity of the content, and learning model in the pandemic. The findings from data analysis of various statistical measures revealed that the think-aloud approach positively impacted ELLs' problem-solving performance and academic language usage in multiple ways. The results were analyzed along with the study's potential limitations to make recommendations for future research studies.