The analysis of circumstance adverbials in this paper was based on L1 and L2 corpora of student presentations, each of which consisting of approximately 30,000 words. The overall goal of the investigation was to identify specific functions L1 and L2 college students attributed to circumstance adverbials (the most frequently used adverbial class in the data) in relation to packaging the informational content of their presentations and their perceived level of formality of the genre. The analysis revealed differences in the range of functions the adverbials served in the L1 and L2 presentations which, in turn, pointed to differences in the participants' perceived level of formality and degree of interactiveness of the speech event. The L1 presenters seemed to perceive the academic presentation as an opportunity not only to present information in an informal way, but also to interact with the audience and keep it involved in their presentations. By contrast, the L2 presenters seemed to be preoccupied with the informational content of their presentations, frequently to the exclusion of their peers from the process of information negotiation, which suggested a more formal and informative function they attributed to the presentation as a speech event than the native speakers. (Contains 3 tables.)