This study investigates how newcomers to the university setting integrate lexical bundles (LBs)--frequently recurring word sequences--into their writing by analyzing the bundles' "syntactic roles" (i.e., relations to larger structures). Previous studies have considered phrases and clauses as the main internal structures of LBs; however, these boundaries might not always be clear because such fragmented sequences do not stand alone, but are embedded in larger structures. The current study addresses this gap by investigating the syntactic roles of LBs identified in native and nonnative corpora of English argumentative essays (approximately 1400 essays, comprising half a million words each) written in response to identical writing prompts. The results show that the two language groups display generally similar patterns of using LBs due to their status as novice academic writers, but at the same time, their patterns do diverge to some extent, with some uses unique to or more common to each group. The extent to which different population groups use LBs in relation to the syntactic complexity typical of a given register could be indicative of their language development.