Esperanza! Well hello!
I just re-read my previous post. The grandchild thing pertains to getting work, but I have to double check on the citizenship thing! Good catch! Sorry, but to give you some more information read on! Well, yes, it could be that you were mis informed, kinda... I'll need more details. You said your Grandparents were from there, right? So your parents are 1 generation american citizens?
I'd have to look into it. To WORK in Spain now, grandchildren or children of Spanish nationals of orign SUPPOSEDLY have the same rights as any other spaniard seeking work. That's fairly new, and hasn't really caught on yet, but it is possible, especially if you know someone with a business. That and hire a lawyer and they should be able to make it work!
Regarding asking for Spanish Citizenship:
as far as I know, one of your parents has to be a spanish national of origin. Here I'm not sure if the grandchild thing would work for this or not. I may have some paperwork at home that may tell me, I'll check for you. If it doesn't, you may be out of luck, but not really. Kinda long, so be ready. Technically, if your parents are originally from spain, no matter where they may have moved to or if they have taken up another nationality, they are ALWAYS spanish. But ONLY IF they didn't give up their spanish nationality, and to do this, in the eyes of the spanish government, they have to go to a consulate or spanish authority and inform them that they have renounced their spanish citizenship. And, technically, if your parents are spanish of origin, even if you were born outside of spain, well, it gets passed onto you( and so on and so forth- apply this to parents being your grandparents, and you being your parents, and see where that puts you. If your parents are spanish, then technically, so are you). Here is where it gets very grey.... if they resigtered you at the consulate, or in spain, that's good- less complicated. If not... well, that's a tough one. The more distant your ties get from spain, the harder it gets. Being american or half american is even worse because we don't have the advantages of Spains other colonies, as many of the Latin American countries have agreements with Spain and they can opt for spanish nationality by other means. We don't
So, if your parents were born and/or raised here any may have been as american citizens, it could be that you do not have this option. On the upside, if you got work there using the grandchild rule, then you'll also eventually get a permiso de residencia indefinida, and with that, you wouldn't need spanish citizenship- but if you did, well, you have to wait 10 years to apply for it. (so unless you want to move there, pretty much for good...)
HOWEVER, if your parents are spanish citizens, you only have to live there legally for 1 year and then you can apply for spanish citizenship. You should know though, that by doing this, you have to give up your American.
Things are also a bit more complicated if they are, but never registered you in the family book and depending on your age etc. If they didn't but they are spanish, hire a lawyer! It will save you some sanity and probably a few years of running around, like I've had to do!
Let me know if I've confused you enough, or if you have more questions!