Duolingo has its place to teach the extreme basics of a language and to get your feet wet in a language, but once you know that stuff it's time to move on. It also can't teach you anything beyond a beginner level with Duolingo. There's heaps of methods that one can use to learn the basics, the rest can be learned by having a lot of conversations with native speakers. It doesn't surprise me that it was something relating to Japanese. The amount of degenerates that learn Japanese make me facepalm.