C06 will investigate different aspects of non-native addressee register. The focus is on the question of how native speakers shift to a different register when communicating with non-native speakers. The project will extend previous studies by (i) exploring non-native addressee register for non-native speakers with varying levels of proficiency, (ii) analyzing different linguistic levels and building a holistic model, (iii) applying an experimental approach that elicits natural conversations with balanced task roles, (iv) manipulating degrees of awareness and cognitive load in order to gain insights on how controlled and/or automatic various modifications are, and (v) evaluating whether the non-native addressee variants actually improve the comprehension of the targeted non-native speakers.