<p>This study investigates the effectiveness of translation-based learning in enhancing vocabulary retention, comprehension, and learner confidence across different proficiency levels among English language learners. While the use of translation in language learning has been debated, research on its impact at varying proficiency levels remains limited. This study aims to address this gap by exploring how translation influences vocabulary acquisition, reading comprehension, confidence, and recall speed. A mixed-methods approach was used, involving 289 participants from diverse educational settings. Quantitative data were collected from 270 learners through structured questionnaires, vocabulary assessments, and comprehension tests. Qualitative data were gathered from 30 participants through focus groups and semi-structured interviews. Data were collected in three phases—pre-intervention, intervention, and post-intervention—over a two-month period (March 1–April 30, 2024). The analysis of quantitative data was conducted using SPSS, while NVivo was used to analyze qualitative data. The findings revealed that translation-based learning significantly improved vocabulary retention and comprehension, with learners showing increased confidence and faster recall. These effects were most notable among beginner and intermediate learners, while advanced learners showed more limited improvements. The study highlights the potential of translation as an effective tool for language learning, particularly when tailored to learners' proficiency levels. By examining the impact of translation at different stages of language acquisition, the study provides valuable insights into how translation-based methods can be adapted to meet the specific needs of learners at various proficiency levels.</p>