Schools in Chennai are either run publicly by the Tamil Nadu government, or run privately, some with financial aid from the government. The medium of education in private schools is English. Government run schools offer both English and Tamil medium education, English being preferred by a majority. Private schools are usually affiliated to the Tamil Nadu State Board. A few schools are affiliated to the national CBSE board, ICSE board, Anglo-Indian board and the Montessori system. A few schools also offer the International Baccalaureate and the American systems. Schooling begins at the age of three. After two years of kindergarten and twelve years of schooling, students take up non professional or professional university courses.