It's more like a game than actual learning.... which would be great if it worked. I found myself recognising patterns and subconsciously "cheating" while using that app. Nothing beats full immersion in a language and actual real life teachers.

I moved to Spain a few years ago and Duo Lingo had me thinking I understood loads of things when I really didn't. Not in a real life setting. It is good as a side lesson but not great otherwise at least from my perspective.