Interlanguage Development and Auxiliary Verb Errors in EFL Writing: Insights for Intercultural Understanding and Peacebuilding in Diverse Indonesian Classrooms

Abstract

This study examines auxiliary verb errors as indicators of interlanguage development in Indonesian EFL learners’ descriptive writing and explores their broader implications for intercultural communication and educational peacebuilding. Thirty descriptive texts written by tenth-grade students at SMA N 3 Salatiga were analyzed using qualitative content analysis based on error analysis frameworks. Five major types of auxiliary verb errors were identified: omission, misformation, overgeneralization, misordering, and unnecessary insertion, with omission emerging as the most frequent. These patterns reveal learners’ ongoing internalization of English grammatical structures and highlight the influence of L1 transfer, rule simplification, and emerging fossilization in interlanguage development. Beyond their linguistic significance, the findings underscore how grammatical accuracy contributes to clear expression, reduces misinterpretation, and supports respectful communication in culturally and religiously diverse classrooms. As English increasingly functions as a global lingua franca for interaction across differences, improved auxiliary verb mastery enhances learners’ ability to participate in intercultural dialogue and fosters peaceful, inclusive classroom engagement. The study recommends explicit, contextualized grammar instruction, scaffolded writing support, and iterative corrective feedback to promote both linguistic competence and intercultural communicative readiness. These findings contribute to applied linguistics research and offer insights relevant to peace-oriented educational practices in pluralistic learning environments.