Recent work on the elements uh and um has focused both on their functional profile and on the sociodemographic patterns of use. They have been shown to be more than just a signal of some trouble in the speech production process; they also perform text structuring functions that are usually ascribed to discourse markers. And their use has been shown to stratify according to gender, age and level of education (e.g. Tottie 2011, 2014). However, such work has not always been sufficiently controlled for context. Differences that were identified for specific speaker groups may ultimately have been caused by different speaker roles or by differences in the formality or privacy of the communicative situation. For this reason, we focus on one single communicative situation, service encounters in selected and socially stratified Los Angeles restaurants. And we focus on one single speaker role, the role of the server. This allows us to test hypotheses about gender differences and socio-economic stratification in a much more controlled environment. In addition, we provide a functional profile of uh and um in this carefully delimited context, and we show that they are not only used in their often-described functions as planners, hesitators or repair managers but also with a highlighting or a face-mitigating function. The highlighting
function turns out to be particularly prominent to emphasize food terminology when servers present menu items to their guests.