If you are a student in a Duolingo for Schools classroom, it is possible that your teacher has disabled certain things in the classroom settings. If you want those back, you can either ask the teacher to adjust the settings, or leave the classroom.
Examples of what teachers can hide and limit:
- Mature vocabulary (beer, wine, etc.)
- Forum access
- Following friends
- The Flirting bonus skill
Due to COPPA rules, it is possible that you have limited access to certain social features if you have indicated that you are under the age of 13.