They just speak to everyone like they are It's a bad habit. I have a couple of family members who are teachers and they both do it.

I had one good friend who was a teacher and a lush who would just talk to you like a normal person. One day I was out with her and some of her colleagues and I said to them "the great thing about Rachel is that she talks to adults differently to how she talks to the kids" and they were like "lol, no. How she talks to you in the pub is exactly how she is in her classes too." Then she had to move schools and we lost touch.