Everyone has a method of learning but over time we've learned classrooms with one on one teacher interaction works.
Duolingo has not learned this.
I am trilingual and tried Duolingo for 180 days. I tried free, paid, etc. It did help me learn vocabulary words NOBODY KNOWS.
Like for example, "camarero" for waiter. Sorry, the word is "mesero." Or "Boligrapho" for pen. Sorry, the word is "Plume."
There's pronounciation. Duolingo has people saying the word Yo as "Joe". No, nobody says "Joe quiero taco bell." We say "Yo."
Also there's "Elle" which Duolingo pronounced "Ejje".
That's core language stuff. Then there's the site. Many times (Android, Linux, Crome, Firefox) it wouldn't let me click on a word.
Sometimes when I had to speak it wouldn't "recognize" one word and while I repeat it perfectly (with a fluent Spanish speaker at
my side) it refused to accept it.
I don't care if they use AI (LLMs) or humans or trained monkeys. It's a piece of crap.
All that is about the language learning part. Bad vocabulary, bad pronunciation, failure to recognize, and bad website.
But the damn thing emailed me daily "reminding" me to keep my "streak" going and "my friends'" streaks. I tried to turn
it off but to no avail.
Duolingo is a piece of crap. I credit them with teaching me vocabulary words nobody else knows, filling my mailbox with
exhortations, and generally being annoying.
Can't wait for their inevitable exit from the market.
I speak three languages. I wanted to be able to converse in Spanish. Half a year later I hate them so very very much.