1. Click on View Profile in the top right.
2. Go to Edit Profile and scroll down to the Languages Section.
3. Click on + Add Native Language or + Add more language and edit your language information.
The maximum number of languages one can add is 8. This includes both the number of languages you can speak and the number of languages you are learning. At this point, you cannot add more languages to your formal profile so if you do speak more than 8 languages you are amazing and can add these additional languages to your user description!