Instead of an answer I just got a few grunts and then silence.
That sounds paranoid, haha, but it’s actually all about showing respect to those with higher status than you. Anyone in your family who is older than you, any stranger of equal or greater age, employer, customer, teacher, etc.
This may be difficult for non-Koreans to accept, but if a person is superior to you, you should never use their name or say “you”.
I have already been Kimchi Man’s girlfriend for a few weeks when I realized I don’t know his parents’ names!
Feeling like a bad girlfriend, I asked him what their names were.
All their lives they had been called sister, daughter, Ms., mother, wife, and they never needed to use their names. Did you know that ajusshi and ajumma used to be terms reserved just for family, meaning aunt and uncle?
Even if you don’t speak Korean, if you have watched Korean dramas you are probably already familiar with some of this. Well, same thing happened with the it used to be exclusively a family term meaning older brother, but its meaning expanded to mean unrelated older male who you have somewhat close relationship with.
What it hasn’t changed is implied respect and superiority of the person you are addressing, and that is something most non-Korean women using this term don’t understand. Older person is anyone who was born in the year prior to your birth.
However, addressing other people in Korean language is never that simple.
To truly understand the meaning of the word oppa, you must understand a bit about Korean culture.