The problem with not speaking Spanish is that I often do not know when the controller and whoever they are speaking to, have finished their conversation. It must get quite irritating when I cut in on top of them. Should I learn Spanish?
I also find it quite useful on occasions with lengthy delays (Madrid in snow for example), to get a Spanish speaking member of the crew to listen on the P3 headset to exactly what is going on and who is getting what. It is always a revelation. Maybe it's me, but I think if you speak the lingo, you might be at a commercial advantage.
Safe flying everyone....