In my experience, the actual quality of language learning seems to vary widely by language. I'm learning Dutch, and the "guidebooks" for each section, which are supposed to give you important tips, information, etc, are simply a list of some of the phrases in that section. Nothing else. So if you can figure out the grammar rules from the context and examples, great. If you can't, there is no explanation anywhere of exceptions to the rules, why you use one pronoun but not another, explanations of the odd phrasings you will inevitably see in a foreign language since everything doesn't translate perfectly to English, etc. You find yourself searching through chat discussions in the app (because other users are also confused) and Googling internet sites to fill in the blanks. By contrast, Japanese has a whole separate module for writing practice (makes sense since it's a different alphabet), explanations, and extensive guidebook notes for special grammar rules, tips, and things to understand about the language. Really helpful! But why doesn't it exist for Dutch? There doesn't seem to be any attempt to create a consistent user experience across languages.I think the app is also missing the ability for the user to decide what you need more practice on and in what way. I appreciate the practice from Duolingo, but if I know I'm weak in certain words, phrases or ways to communicate (i.e. translating full sentences), there's no way for me to create targeted practice sessions for myself. And the lessons are so integrated between each "step" on the journey that you can't just repeat a specific step or set of steps to feel like you are getting more practice in the specific area you want.Having said that, the price is decent, I like the (somewhat childish) interface - works for me, lol, and my streak is key - and the fact that it randomizes the examples and practice so you are using old words, new words, and learning phrases at the same time to keep you sharp. Overall, to be successful with this app - at least for Dutch - you have to be very, very self-directed and willing to go outside of the app to search for information, quiz yourself, and put the pieces together. There is benefit to that - you remember it if you have to go find it yourself - but I do think the app falls short in basic ways that it shouldn't, especially after being around for so long. I would like to see more of a focus on refining the language app in meaningful ways (not just moving lessons around) versus adding apps for math, music, etc.