The influence of working memory and proficiency on phraseological growth: A longitudinal study of adjective-noun combinations in Chinese EFL learners’ argumentative writing

Phraseological knowledge has gained popularity as a critical predictor of writing assessment in second and foreign language (L2/FL) learner corpus research. However, past phraseological studies on learners with different levels of language competency have overlooked multidimensional collocational indices and the potential influence of cognitive characteristics. This study, employing multiple collocational measures, tracks the growth of adjective-noun combinations in the English argumentative writings of a longitudinal cohort of 148 Chinese EFL learners over four months and explores the effects of language proficiency and working memory (WM) on their phraseological growth. Our findings revealed a general upward pattern in learners’ overall development, despite some slight fluctuations. Notably, the mixed-effects models indicated that time alone had a negative impact on learners’ use of high-frequency, diverse, and strongly associated combinations. However, language proficiency and WM modulated this process, as learners with higher proficiency or greater WM demonstrated temporal improvement across most indices. The interplay among time, language proficiency, and WM presented a more complex image in which high-proficient learners showed a sloping trend on all collocational variables as WM capacity increased, suggesting a potential impact of cognitive overload. These findings offer valuable insights for teaching and identify prospective directions for future research into phraseological knowledge development.