Hello Airyn, "I", the first person singular in Korean has two different versions: a plain one and a honorific one as follows: 나 (는)= na This is the plain humble "I" . can be used when talking to close friends, someone who is fairly younger than you, possibly to close family members including parents and grandparents. But, you should not use this when you talk to school teacher when you are in school, boss, older people, and so on. 나 is mainly used in 반말. "난 지금 많이 바빠요 I am very busy now 저 = jeo This is the polite version of 나. It is used, for example when you talk to older people, teacher, boss, higher rank (in military for example), older family members. 제가 자장면을 시켰습니다 I ordered a Korean style black noodle.