Hi i walked the norte without really knowing spanish. the words you should really look at are directional ones, left, right, straight on, near, far, close and similar words. Also learn how to ask where the albergue is, or where the hospitallero lives(thats if the keys are kept there) or where the signing in book(and keys) are kept, and with that learn the forms of address(politeness) this is quite important. This might sound much, but it is easier than you think. keep a written note with these words close at hand when walking, so if you forget you can either look at them or point out the words to the person you are trying to ask the question.
I got by you pick up words as you walk, either from spanish people who speak english, or other more knowledgeable pilgrims. If things seemed to be really bad, usually a german would turn up with their guide just as things were getting interesting.
Bueana Fortuna
Mike