> I was never quite sure when to "tu" and when to "usted" - its probably one of those things that makes a foreigner look quite rude in Spain.

It’s so hard for me using the same “you” with a friend or with a stranger!.
We use “tu” with friends, family or young people, and when we want to slight a stranger. We even have the word “tutear” that is using “tu” with somebody. And we can say with dignity: “How do you (usted) dare ‘tutearme’?”.
One sad experience that almost every Spaniard have to undergo in his life is when for first time a stranger young person address you using “usted”. You think “How a boy like me is using ‘usted’ when talking to me?. Or, maybe, I’m no longer a boy?”.


Juan Maria.