Yeah, half-heartedly doing French in Duolingo for a few years meant that I knew a bunch of words and could read stuff okay, but communicating and thinking in French was incredibly difficult. I took a couple of classes IRL to fill in those other skills, so now I can actually get by as long as people are a bit patient with me. It was easier for me to learn that stuff than other people in my classes because I had Duolingo experience, but Duolingo definitely isn't enough on its own.