The proposed project aims to investigate the role of gestures in human interaction, with particular attention to the communicative function of co-speech gestures by native speakers of Dutch, Chinese and Chinese learners of Dutch. If speech and gesture together form language, and both are used for communicative purpose, then speakers can be expected to adapt their speech and gestures to their addressees. Also speakers may use gesture as a communication strategy in disfluencies. However, our understanding of these issues is limited, and many questions remain. First, how do speakers adapt their gestures to their addressees in non-native speaker situations? I.e. Chinese learners of Dutch speak in L2, or native speakers of Chinese addressing Dutch learners of Chinese. Secondly, how Chinese learners of Dutch use gestures to deal with disfluencies-related problems? And lastly, in what different ways do L2 learners' gestures facilitate addressee's comprehension compared with L1 gestures, given that L2 speakers with different proficiency levels vary their gesture production in terms of gestural appropriateness, gesture types and gesture frequency? In order to gain some insight into these issues, gesture production will be investigated in two conditions: 1) in L1 and L2 communication between Chinese and Dutch speakers; 2) in conditions with variable visibility between speakers and addressees. There will also be a close examination of L2 learners' gesture in disfluencies. Furthermore, a comprehension experiment will be conducted to investigate how gestures by L2 learners can facilitate addressees' comprehension. The results of this project will provide a better understanding of the communicative function of gestures and the relationship between speech and gesture. Additionally, it will give valuable insights into the processes of second language acquisition (crosslinguistics influence and language transfer) and contribute to its theories as well. Furthermore, the findings from the study on the Dutch and Chinese gestures will also be of benefit to the domain of cross-culture communication.