There are three basic ways to greet someone in Korean, depending on what
degree of politeness and/or formality the situation requires:
안녕? (Very casual – not used among adults)
안녕하십니까? (Honorific, formal)
1) Generally, you should use the honorific form:
2) However, when a student greets a teacher, the formal expression can be
Student: 선생님,1 안녕하십니까?
3) And when two young people bump into each other on the street, they can
just say 안녕? (An-nyeong?).