Not only do your answer's need to be perfect in order to progress but you can also answer correctly without knowing why you are correct. Most people manage to

Not only do your answer's need to be perfect in order to progress but you can also answer correctly without knowing why you are correct. Most people manage to speak their native language just fine but very few speak it anywhere near perfectly. Obviously, you need to learn the basics of grammar in order to construct a sentence that sounds more or less right but I'm not sure Duolingo can even do this with any degree of success.