Duolingo is a pretty bad tool for learning a language, it's good to make you feel like you're learning though.

I finished the whole tree in French and had nothing to show for it either. It really is a fun way to feel like you're learning, without connecting you to the language or culture in any significant way.

For me - nothing beats in-person classes in lieu of a native speaker whom you can interact with. Being forced to actually speak the language in “mock settings” makes all the difference.

And even if you don’t get your grammar completely right, you will learn enough to survive in a real-life setting.

I learned Spanish through a combination of both - I took Spanish classes after I started dating my Mexican wife, enough to get conversational. Then I started interacting in Spanish with her family, which helps me now maintain the language without needing the classes.

I feel this whilst learning (trying to) German: when I think "how I would say this in German?" I got nothing less than a blank on my mind. But I'm a good "speaker" though, and sadly, I feel I'm not going anywhere as well...

That seems to be a pattern

Anki is the way, especially with their new FSRS algo.

Likewise, but also about that with Arabic on Duolingo and I never even mastered the alphabet.