Okay, I have been using Doulingo for about three to five years, and I can say that its an alright application; However, there are some problems I start noticing. Mainly, in some of the most recent updates, the people they got to do the pronounciation seem to struggle a bit with the words, another thing I notice was the grammar problems, there's also the problems with all the constant updates that make you lose track of where you're at. In the end, just by a book to study or a different app.