We tried 5 years ago when we last lived in Switzerland to put him into a local kindergarten but the teacher was not friendly (a fact agreed by many others in the neighbourhood) and so we moved him to an English school. So he has about 6 months swiss german and then the minimal german learnt in the english school. This time will be different as he is more interested in school and more socialable. He is bilingual in 2 other non swiss languages.