Go to Learning Language under your settings. In gray type you will see reset or remove language. You can choose to "reset" or "remove". If you choose remove, then you will need to go back and add the language again. Note the "be careful" notice. I think it will make you start over with everything in that language -- but that will be a good review though. I've only been on Duo for 52 days - so maybe someone with more experience can add to this. Good luck!