We entered Thailand in June 2021 on a tourist visa and then switched to an education visa to study Thai at a private language school. We would really like to study Thai for another year at the same school. Is there an official rule for how many years one can study at a private language school? If it’s possible for us to stay on an education visa for a second year, can we renew our visa within the country or do we have to exit/re-enter?