During our second week in Granada, after my parents headed home, a language school about five minutes from our house agreed to do 90 minutes of classes/day for the three kids. They had a lovely teacher named Lola, and I had just enough time to dash down the mountain and do or see one thing before picking them up again! I think the older kids could have handled more, but that was about the max for Mac.
They learned quite a lot for a week!