Attitudes of Pakistani Undergraduate ESL Students toward Artificial Intelligence in Improving English Writing Skills

English writing proficiency is vital for educational, professional and personal development. With the rapid growth of Artificial Intelligence (AI) in academia, understanding its impact on language learning is essential. Students' attitudes toward AI influence their motivation, engagement, and learning outcomes. This mixed-method research aimed to explore the attitudes of Pakistani English as a Second Language (ESL) undergraduates toward AI in improving writing skills. Perceived usefulness, ease of use, and behavioral intentions of ESL undergraduates toward AI are examined through the integration of Technology Acceptance Model (TAM) and Constructivist Learning Theory (CLT). This study also investigated the influence of motivation, engagement, and societal expectations on AI adoption for improving writing skills along with the constructivist learning strategies used by students. Quantitative data were collected from 215 students through a Google survey and semi-structured interviews were used to gather qualitative data from 10 students. Descriptive statistics and percentages were used to analyze quantitative data; however, qualitative data were analyzed through thematic analysis. The findings highlight that ESL undergraduates' attitudes are strongly influenced by perceived usefulness and ease of use; however, attitudes and behavioral intentions received slightly lower scores. Furthermore, challenges related to over-dependency, ethical considerations, and subscription issues affect AI adoption. Motivation and societal expectations increase AI adoption; on the contrary, learner-centered and interactive approaches are needed to enhance engagement levels. Additionally, this study suggests the need for AI ethical guidelines, institutional support, and literacy training to fully benefit from AI tools in improving writing skills.