To what extent do L2 learners produce genre-appropriate language? A comparative analysis of lexical bundles in argumentative essays and speeches

L2 English learners are often reported to incorporate features of spoken language into their academic writing, blurring the lines between written and spoken genres. However, previous corpus-based studies have predominantly focused on L2 writing, leaving L2 speaking relatively unexplored. It is thus unclear whether learners lack genre awareness – as previously claimed – or if they indeed attempt to differentiate their language across genres, but lack ability to do so. This study explores lexical bundles in academic L2 English in parallel corpora of written and spoken data produced by the same learners, with the same prompts pertaining to argumentation. The findings show that learners employ phrasal/referential bundles, typical of academic prose, significantly more in their essays than in their speeches, where clausal and stance-expressing bundles are more prevalent. Notably, the students were found to employ identical bundles differently in argumentative essays and argumentative speeches produced in response to the same prompts. This finding implies that learners may have a better understanding of how to use formulaic language in both spoken and written genres than previously believed, suggesting that they are aware of genre distinctions, although other factors related to mode (e.g., the cognitive demands of speaking vs. writing) are likely to be involved as well. Furthermore, in comparison with previous findings on L1 bundles, these findings hint at the possibility of argumentative genre conventions unique to L2 learners, in which, broadly, L2 argumentative speech resembles an L1 conversational genre, while L2 argumentative essays seem to navigate a middle path between conversational and academic prose conventions.