Foreign and programming languages.
After a while of learning English by myself i realized that i wasted lots of time being focused on apps for learning. I was a huge fan of Duolingo app. It is as amazing as Sololearn and i have a feeling that sololearn-developers were inspired of the app and decided to create something similar but about programming. So i came to a conclusion that if i would started the learning of the language from some structured texbook with audio, speaking exercises and so on, i would became a fluent already. The same i feel here, on solo. Going to find some author that has textbooks from beginner to profi, step by step. This app magically involving to the programming world but not gives necessarily skills to become professional i am sure. And there is also one wonderful thing as it seems to me - you can try many basic courses and choose what suits to you and some structured learning materials that i mentioned. What do you think of all of that and what author you would recommended me in this case?