No you don't.
I'm French, I dropped out of school at 16 and picked up English later in life without using any formal method of learning. I started by memorizing enough vocabulary to read simpler English, after which I began reading popular fiction and watched movies with subtitles (in English) until it clicked. My understanding of the language is more based on intuition (sheer memorization of exposure to it through cultural mediums) than on memorizing the grammar rules book. The brain makes the connections as to what seems correct or not based on patterns. I don't think my skills are good enough to write literature but surely communication isn't a problem.
Duolingo didn't exist at the time, but I believe it would have helped me learn faster considering the way it introduces languages is quite similar to how I started learning and it does so in a more interactive, fun manner.
No you don't. I'm French, I dropped out of school at 16 and picked up English later in life without using any formal method of learning. I started by memorizing enough vocabulary to read simpler English, after which I began reading popular fiction and watched movies with subtitles (in English) until it clicked. My understanding of the language is more based on intuition (sheer memorization of exposure to it through cultural mediums) than on memorizing the grammar rules book. The brain makes the connections as to what seems correct or not based on patterns. I don't think my skills are good enough to write literature but surely communication isn't a problem.
Duolingo didn't exist at the time, but I believe it would have helped me learn faster considering the way it introduces languages is quite similar to how I started learning and it does so in a more interactive, fun manner.