Write a novel, and learn a language. I started writing a sword and sourcery novel on my rail commute, and its been much more fun than listening to fantasy audi

Write a novel, and learn a language. I started writing a sword and sourcery novel on my rail commute, and its been much more fun than listening to fantasy audiobooks (which are very hit and miss in quality). I've previously learned some French, German and Mandarin Chinese. I'd like to reach the threshold where I manage conversation in one of them by the end of the year. My Mandarin learning is most recent, my German was the most in-depth, and there's a French programmer working next to me. I dont know which one to do yet!