I will start and state that I am an American. As I teach here in Korea I have found that Koreans think it is the right way, culturally, for a student to call a teacher by his/her first name. I think this is a cultural mistake. It is not OK for a student to call a teacher by his/her first name. (Or have thinsg changed that much since I was a student?) Are their other English speaking countries where calling a teacher by his/her first name is considered the norm?

What other cultural errors have you found from your host country?
And what cultural errors did you make in your host country?

Most of the students I meet in Korea believe that all western people wear their shoes in the house.

I suppose maybe there are some people who do, but I would say as a norm most people take their shoes off at the door.

I'm the opposite - I've always had all students of all ages call me by my first name. However, 95% of my teaching has been in private language schools, where things tend to be a little less formal than in "proper" school.

My advice would be to follow the lead of the other teachers already established in the school. If first names for teachers is normal there, then go with that.

I'm American as well, and while I didn't call my earlier teachers by their first name, I did call most of my college professors by there first name.

When I worked in a hagwan, I think a lot of my students called me by my first name, but a lot of them added teacher or sunsagnim after it.

I'm at a public elementary school now and they all add teacher or sunsangnim at the end. Once in a while they just use my first name, at first I didn't mind, but I noticed the Korean teachers always corrected them. So now I do as well.

However, if I am walking around my village and some of them see me and run up to chat, I let it slide if they forget to add teacher or sunsangnim. It's nice to see they are excited to see me. Also I figure we are away from school, so I am more relaxed.