And I am glad it exists because of that. I can read any language grammar book and maybe even try some exercises but what only Duolingo offers is what's missing

And I am glad it exists because of that. I can read any language grammar book and maybe even try some exercises but what only Duolingo offers is what's missing when you are not in the country : practicing the language every day. (The website is better than the app where you just have to tap the right word in a list of words, you actually have to remember)