Totally echo all of this. I'm one of the owners at the Orange County Lingual Institute (oclanguages.com) and we see Duolingo as the gateway for people to tap into their language learning interest but then get serious with in-person or online language learning classes. We have seen firsthand hundreds of students unsuccessful with apps since they are not practicing live conversations and not understanding grammar. With 80+% retention of our 2 month/once a week classes, adult professionals get through a college textbook in a year and can become fluent enough to travel to those countries, speak with relatives, and read novels & newspapers with high levels of profiency. Language learning is hard work with no shortcuts but can still be accessible without apps that overpromise and underdeliver. Ping me privately or check out our site for more info.