Throughout the Dune movies, the Fremen are shown speaking the Fremen language. As Duolingo does add fictional languages which are possible to learn such as Klingon from Star Trek and High Valyrian from Game of Thrones, I believe that adding Fremen would be fun and boost the usage of Duolingo; many people are already dedicated into learning Fremen on the Dune subreddits, so boosting Duolingo download rates would be definite. Additionally, Fremen already has blocks to build off of, Arabic has a huge influence on the spoken language, as well as other languages.

Many people already are learning/want to learn Fremen, so adding it on Duolingo would just be a win-win. The first sections and units can be the words and sentences we that are confirmed (i.e. the sentences already spoken throughout the two movies). Please I want to be as cool as Paul.