This study adopts an interpretive case study design and integrates semi-structured interviews with NLP-assisted text analysis to examine EFL learners’ perceptions of language creativity, writing attitudes and writing performance, as well as their dynamic interrelationships, in argumentative and narrative writing. The participants are six second-year English majors. The findings show that learners’ perceptions of language creativity are both genre sensitive and process orientated. In argumentative writing, they place greater emphasis on logical control and expressive precision, whereas in narrative writing they prioritizes narrative coherence and expressive flexibility. The findings also indicate that learners engage in strategic trade-offs between creative expression and linguistic accuracy in response to genre demands and evaluative expectations. In addition, writing attitudes moderate the relationship between language creativity and writing performance through cognitive, affective and behavioral components, showing clear contextual variability. The NLP results are consistent with the qualitative findings in terms of keyword distribution and sentiment orientation. The study suggests that integrating NLP-assisted analysis into qualitative research can enrich the interpretation of learners’ writing experiences and offers a useful methodological approach to technology-enhanced L2 writing research.