The website Educa.ch provides a detailed overview of the Swiss education system. In Graubünden, children start kindergarten after the school summer holidays in the year they turn five. After two years in kindergarten, children move on to primary school. After primary school (6 years), there are various possibilities to complete the obligatory nine-years of schooling (Gymnasium, secondary school, Realsschule) and continue education beyond that. In Graubünden there are three official languages: German, Italian, and Romansh. Depending on where you live, one of these languages or several languages will be taught.
Links to schools of secondary education in Davos and Chur: