> Number of people I know that used Duolingo successfully to be fluent in a new language: 0 But they say they're "the world's best way to learn a language," ri

> Number of people I know that used Duolingo successfully to be fluent in a new language: 0 But they say they're "the world's best way to learn a language," right there on their homepage: https://www.duolingo.com https://www.duolingo.com. So either no one has ever successfully become fluent in a foreign language (because not even the best tool can be used to successfully accomplish the task), or the tech industry is full of liars and its claims cannot be trusted.