A vocabulary is best when it continues to grow, every day. No matter what language you study. Whether your own language or a foreign one, words are power. Words change your life, they change your knowledge, views and personal vision – how you see the world. A vocabulary even changes how other people see you. The more words that you know, the more that you can do.
A vocabulary is one of the most powerful things on earth that is free. Words are incredibly valuable, and completely free. Go get as many as you can!