I really want to know what the most learned languages are on Duolingo and how many "learners" each one has. Does anyone know? Or maybe the staff could post it. Also if anyone else has any other interesting facts feel free to post them here.
It's my understanding that the most studied language is English.
The above video has Luis von Ahn discussing Duolingo. Around 30 minutes in, he discusses the percentage of users from various countries. Although he doesn't provide percentages for each language, the inference is that English is the most studied language.