From Awareness to Application: Examining the Effectiveness of Usage-Based Grammar Instruction on Adverbials

Abstract

This study examines the impact of explicit, usage-based grammar instruction on adult learners’ metalinguistic awareness and functional deployment of adverbials in an American college writing course (ENG-145). Fifty-one native English-speaking students participated in a pre–post instructional design targeting explicit understanding and application of adverbials grounded in usage-based linguistic theory. Metalinguistic knowledge was assessed using a 26-point pre- and posttest that measured definitional precision and categorical understanding. Results indicated improved conceptual clarity following instruction. To evaluate changes in production, adverbial frequency and distribution were analyzed in pre- and post-instruction writing samples. A paired-samples t-test revealed a statistically significant increase in adverbial deployment from pre-instruction to post-instruction with a large effect size (Cohen’s d = 3.29). Readability analysis further demonstrated qualitative shifts in adverbial integration, indicating greater rhetorical appropriateness and syntactic flexibility rather than frequency gains alone. In addition, overall writing proficiency improved, with a higher proportion of students producing texts at elevated grade-level benchmarks following instruction. These findings provide quantitative evidence supporting the pedagogical value of explicit, usage-based grammar instruction in enhancing both grammatical awareness and meaningful application in college-level writing.