I've been reading similar anecdotes lately trying to gauge whether I could reach B1 in a Romance language in a few months of study.
What I've found is a lot of pessimism about how well Duolingo teaches you a language, with many arguing it's a waste of time altogether.
I'm surprised that could be the case though. They have data from millions of language learners processing through their lessons, and looking at their making-of blog (https://making.duolingo.com), the product seems data-driven. They do A/B testing to see the efficacy of new features they roll out. Aside from that, they combine reading, writing, speaking, and listening exercises, and have made some innovative features like chat bots. One language tree includes a few thousand words.
If anything, I would expect Duolingo to be vastly more effective than other methods.
What I've found is a lot of pessimism about how well Duolingo teaches you a language, with many arguing it's a waste of time altogether.
I'm surprised that could be the case though. They have data from millions of language learners processing through their lessons, and looking at their making-of blog (https://making.duolingo.com), the product seems data-driven. They do A/B testing to see the efficacy of new features they roll out. Aside from that, they combine reading, writing, speaking, and listening exercises, and have made some innovative features like chat bots. One language tree includes a few thousand words.
If anything, I would expect Duolingo to be vastly more effective than other methods.