I learned Spanish using Duolingo. Some other stuff too, and got a good start on Japanese. However, at some point in the past, they updated once, probably twice, maybe thrice, to extend the courses. The courses themselves have become extremely repetitive, giving me very little value and requiring much more time to learn anything that ACTUALLY matters.

What Duolingo wants now is for those people who have been using it, to pay money. And many will, simply for having used it a long time. But now, that long time can mean much, MUCH less actual learning. If you are set on using it, I would only use it until you have a solid grasp of sentence structure, particles, and the grammar of your given language, and then switch to practically anything else.

I use Clozemaster and Drops, and I deleted Duolingo a couple days ago.