Tandem International Multilingual School was founded in 2004 and teaches on four sites around Zurich: the city campus for early years and primary, Küsnacht for the Gymnasium and Grades 5 and 6, and Zollikon and Erlenbach for early years and pre-school. It takes children from birth through pre-school, kindergarten from four, primary from six, and on into the Gymnasium. Teaching runs in German, English and French through a translanguaging approach. The curriculum combines the Zurich cantonal Lehrplan 21 with the UK National Curriculum and the International Baccalaureate Primary Years Programme. More than 300 pupils from 30 nationalities attend, taught by 90 staff from 12 nationalities. Around half of primary leavers continue into the school's own Gymnasium.