On-line accommodation to an interlocutor is often cited as an explanation for phonetic variation. Prosodic evidence for speakers’ accommodation was investigated in a task that was expected to favor modification: giving directions to a non-native interlocutor, compared to the same task with a native interlocutor. Ten native speakers of French were recorded in spontaneous conversation in the two conditions. With the non-native, they used a significantly greater F0 range, and segmental modifications compatible with a more emphatic speech style, but did not modify speech rate or utterance duration. These results suggest that accommodations can include both language-specific and universal properties, and that speakers can selectively implement different ways of accommodating.