Why "add friend" instead of "follow"
I am really confused about using "friends and followers" instead of "following and followers" and very curious about the thinking behind it. To me the English word "friend" should be a bidirectional relationship. Is there any one can explain it to me?
I agree. Adding someone as a friend here doesn't require the other user to accept, and it's just one way, which is a bit of an odd use of the term "friend".
Friend me so you can see my daily point tally in your highscore sheet. I friend you so i can have you in my highscore sheet.
I like icehuli's idea of if you add someone, you're "FOLLOWING" them, if they add you then you have a "FOLLOWER", and then I'd add that if you follow each other then you're "FRIENDS."
Of course, to change that and add the third category would be more work for the people writing DuoLingo's code that can probably be better used for making other needed improvements.