I think that only unhappy customers are writing reviews... let´s change that because I believe people don´t really know how to use the app and what they can realistically expect from it. I first made my Duolingo account in 2016, to learn some English (my native language is Portuguese). I was a bit lazy back then, so I didn´t use the app very often.In 2020, I got back and started learning German. I was living in Austria at the time, and the app was an excellent addition to the formal course I enrolled in. Since then, I have used it to learn a bit of a few different languages and to improve my English, as I had to take a proficiency test not long ago.The thing is.. you cannot think that the app will make you fluent, especially if it is the only means you use to learn the language you are studying. And yeah, the courses may have a few errors, but again, you need to study from other sources too. And you need to USE the language - watch movies, listen to music, attempt to have conversations... and be patient. Language acquisition is a complex and time-consuming process. Don´t blame the app for your unrealistic expectations...Also, do some research about Duolingo for Schools. It´s another very nice resource!