This study focuses on the relationships between host family success, social integration, length of stay and acquisition of adolescent language by students on extended international homestay programmes. Degree of adolescent language acquisition and integration is measured by use of two hallmarks of adolescent language: markers of approximation (e.g. "and stuff") and intensification (e.g. "like"). Participants are 26 German teenagers on either a 5- or a 10-month exchange to Australia. Their use of approximation and intensification markers is measured quantitatively before arriving in Australia and then after 5 months of living in the host country. Host family relations and levels of social integration are measured qualitatively by analysis of interview content and responses to a Language Contact Profile. Results indicate that there is a direct link between host family relations, social integration and acquisition of markers of adolescent language. Additionally, exchange students on a 5-month exchange use fewer of those approximation and intensification markers most associated with Australian adolescent language than students on a 10-month programme. This can be explained by lower investment and integration in the Australian adolescent community.