In September 2017 I had the opportunity to take Spanish classes in Barcelona. I had classes for two weeks at the B1 level and it was a positive experience for a number of reasons.
On the first day everyone learned rule number one: we had to speak a lot and we had to speak in Spanish. My classmates and I came from all over: Germany, Austria, France, Brazil, Australia and Canada. Because we came from all over, to be able to communicate, we spoke strictly in Spanish. In my opinion, there is no more effective way to learn and improve upon your Spanish.
We did not need much time at all to become friends. In addition to learning from our teachers at the Spanish school in Barcelona, we learned from our classmates because of their different experiences in life and their different points of view. In class, we talked about everything under the sun and of course we talked about grammar too. The style of teaching, the energy and good humor of our teachers made class time fly by. My only regret was that I could not extend my Spanish program in Barcelona for another two weeks because I did not have enough time.