The project consists of an exchange, between students and teachers, of experimental and CLIL activities that can be used both to improve the understanding of the topic (hydrostatics, that is common in the curriculum of Physics of the schools involved) and to improve the vehicular language (English) used by the students and the teachers. The students will plan, analyse and discuss the activities that are suggested by the teachers and compare their results with their colleagues. In the end they will create video-lessons about the topic.