just a heads-up here lads & lasses...
i was lucky enough to live in barcelona for a year and i pretty quickly realised that the majority of them do not consider themselves to be spanish.
barcelona is in catalonia & they are incredibly passionate about independence form spain,
so much so that they have regular marches through the city.
you will find they are very fluent in english so there's no problem communicating at all
and although they understand spanish they would rather you don't speak it to them.
(a few of them actually find it insulting and ignorant)
on first hearing, catalan sounds like a mix between spanish and french but it is a separate language of its own developed from latin 1000yrs ago
it was actually made illegal to speak or write in 1940 by the fascist dictatorship in power in spain.
it is now the official language - taught in school - even the newspapers use it.
so if we intend to greet them nicely - it's best not to call them spanish or speak to them in a language that represents everything they reject.
there are some words and phrases on here if you are interested
<a class="postlink" href="http://wikitravel.org/en/Catalan_phrasebook" onclick="window.open(this.href);return false;">http://wikitravel.org/en/Catalan_phrasebook</a>