It depends on what you think when you say to learn a programming language. If you mean catching up with syntax then I would suggest some language that is clearly written and similar to english, e.g. visual basic or python. However, every language is the same in it's basis, at least as far as it goes for object oriented programming languages. When you learn one OO language then it's quite easy to learn others, it's only the matter of getting used to different syntax. But to truly learn to program in any language takes a long time. I think it takes around 5 years to really master programming. From that point on you should have enough experience to use any programing language that suits your task the best.