Oh no I understand that. I'm just saying that the phrases are informal...I just think if one is going to learn a new language you should at least teach it in a formal matter so one isn't being disrespectful...... but I guess not?
@JackieSung I find that people here are more wanting to learn the phrases they will hear commonly, which tend to be informal. Many of the learners are not interested in going to Korea seriously to live, and if they do, they most likely have another source of learning that gives them the understanding that you have. But I'm not so sure on the thinking process.