It depends how much you work and how good you are at learning languages, Spanish and English are very very similar languages, a ton of words are almost exactly the same, I'd say if you spend a lot of your free time studying, have a natural capacity for language and preferably already know German maybe two years for passable English? In school you're supposed to take four years to learn fluent Spanish, but then again school language classes go incredibly slowly-it depends on your effort.