Would I be able to master Spanish by going to a foreign counrty for a year?

Good idea. I've heard that that is the best way to learn a language. Sadly we don't all get the opportunity. And yes. The basics/most useful is key! Learn the preterite and infinitive, and present progressive as well as present for er/ir/ar verbs. I suggest going to Venezuela or Colombia because I hear their spanish is most proper. Spain is good since it is the mother country of the language but you would have to get used to their accent (instead of ''s'' they pronounce it somewhat like ''th'') and they are the only country to use vosotros so you would have to learn that form of all of the verb forms.