I was thinking that maybe Duolingo could add a small quiz or something at the end of each section (i.e. Basics 1, Animals, etc.) so that we can test our knowlegde and see if we have actually learned the content. I was thinking that maybe it could be 10 questions long asking about grammar, concepts and vocabulary.
Would this really make a difference? I feel like duolingo is constantly testing our knowledge. If we haven't learned what we're supposed to learn then we won't pass the lesson or the section, if we manage to get through on luck then we'll soon realise it in the next lesson or section as it builds on previous knowledge.