You are saying about 저는(jeoneun) which can be pronounced as 'chonun' by English speakers. And let me explain about it. 저(jeo) is a humble form of 나(na) which means "I" in english. 는(neun) is one of subject marking particle. So, 저는(jeoneun) means "i __" or "I am __" in a sentence. It can be omitted in daily conversations though, the sentence would be more clearer when you put that in. For example A: 이름이 뭐예요? (ireumi mwoyeyo? : What's your name?) B: 알렉스입니다. (alex imnida : I'm Alex) A: 누구세요? (nuguseyo? : Who are you?) B: 저는 알렉스입니다. (jeoneun alex imnida : I am alex) As you see, it is used when you emphasis a word or thing. You : 너(neo) Me : 나(na) But you can't use the word "너" for everyone. It's only for your friends or someone is much younger than you. Then how about a stranger or someone you're supposed to be polite to? There is a word 당신(dangsin) but this sounds less polite in colloquial either. Because Korean people tend to avoid addressing "you" directly because it might be kinda rude. The best way for addressing a stranger would be calling their titles such as 선생님(seonsaengnim) 아저씨(ajeossi : older male looks married) 아주머니(ajumeoni : older female looks married and having grown up children) *warning: some ladies hate to be heard as this 학생(haksaeng : someone looks younger than you and be like a student) 그쪽 분(geujjok bun : around your age and you have no idea what his/her title is) etc... Hope this helps! ;-)