Getting a GCSE in Spanish can you a false sense of security. Sure, you can order meals, read the newspapers, ask the way and talk about your family. But nothing quite prepares you for that sinking feeling when you start a conversation with your new neighbour and she answers you in Martian.
OK, so the accent is "a bit thick" round here. The letter S is almost extinct, the ground is littered with abandoned syllables, consonants are switched randomly and there are approximately 10,000 Andalucian words that aren't in the dictionary. But if you are going to live here and not be dependent on other people to translate for you you are going to have to get to grips with it.
Fortunately, when using the local shops, the prevailing absence of any sense of urgency can be turned to your advantage; shopkeepers are usually quite happy to wait while you describe what you want with a mixture of GCSE vocab and mime, and other customers often chip in to offer helpful suggestions. The only thing that's defeated me so far was an open-ended zip fastener.
I can sympathise with those British residents who bypass such potentially embarrassing situations and drive 50 km to a self-service hypermarket instead. But for me, it's all part of the challenge. We use local shops and tradesmen wherever possible. We set up weekly "intercambios" with some local residents who want to improve their English, where we speak for half an hour in Spanish and half an hour in English. We did a three-week intensive course at La Janda International School in Vejer de la Frontera, speaking only in Spanish for four hours a day. We go to the local bars and talk about football - always a popular topic, particular as Spain is the best team in the world. Gradually the Martian is starting to evolve into something recognisable, but I think it's going to be another couple of years before we can converse fluently.
People often think that if you live in a foreign country you will "pick up" the language by some sort of immersion process. However in my experience this does not happen. It's all too easy to socialise only with people who speak your language, watch British TV via a giant satellite dish, read English newspapers online, use ex-pat tradesmen to do your building work, etc. At our age, learning a language is not a passive process. You might have shelves full of Teach Yourself Spanish books and CDs, but unless you actually get them out and put in some graft for an hour a day - every day - you will never be able to do much more than order some drinks and a meal.
Useful free online resources for learning Spanish
http://www.notesinspanish.com/ (free audio and newsletter, other resources charged for)
http://www.spanishpodcast.org/ (free audio and transcripts of conversations between native speakers)
If you don't mind splashing out, the Michel Thomas CDs are highly recommended. Just sit back and listen as two students learn by their mistakes. Thomas himself has an irritating accent but there is no doubt that learning by repetition is effective.