What do you think is the right thing to do when you're not sure if the person you're talking to speaks English? I hadn't thought about it (stupid me) before we visited Montreal and sort of defaulted to saying "Hello" in response to "Bonjour", upon which every person we dealt with immediately switched to English. (some of them even said 'sorry', which: !!!)

I usually say 'lo siento hablo muy poco Espanol' in Mexico, but that's different since I do have a tiny bit of Spanish.