I came to study in Siena without knowing much Italian so I signed up with Scuola Leonardo da Vinci. This is definitely one of the most popular italian language school in Siena - glad I signed up here.
I was able to learn some basic Italian that helped me navigate the city while I was here for a few months. The staqff was upbeat, energetic, and really made the classes fun. I've taken language classes before in other countries, but nothing compares to here.