This paper investigates the linguistic and modal aspects of responses made by subjects in a Wizard of Oz experiment to repetition requests made by the ‘Wizard.’ English-speaking ‘clients’ participating in a task-oriented cooperative dialogue with Japanese-speaking ‘agents’ were asked to clarify utterances that were complex or lengthy. The discourse, syntactic, and modal structures of these clarifications are examined. While linguistic factors are characterizable as ‘reducing’ and ‘converging,’ media use in these responses does not exhibit a clear pattern. Implications are drawn for future investigations into the use of multimedia configurations and for the integration of multimedia technologies in automatic speech processing.