This study reports on the development of a professional spoken register among learners of German as they participate in four synchronous Web conferences with German-speaking professionals. The researchers investigated the effect of interaction with expert German speakers combined with an instructional intervention focusing on pragmatic competence on the development of learners' ability to communicate in a second language (L2) professional register. The data reveal a positive effect on the strategic use of modal verbs for expressing polite requests as well as a moderate effect on learners' use of the subjunctive mood to establish social distance. These results add further support for the use of intercultural online exchanges mediated by data-driven instruction in the foreign language classroom and highlight the utility of a microgenetic approach to analyzing spoken data. (Contains 3 notes, 2 figures, and 4 tables.)