It depends on your gender.
If you're a girl, your older sister/an older female is your "unnie" (uh-nee)
If you're a guy, your older sister/ an older female is your "noona" (noo-na)
A younger brother or sister is your "dongsaeng" (dong-seng)
Dongsaeng is used regardless of your gender or the person's gender.
dangsin-ui yeodongsaeng eul mesinjeo
oni, sa na ei yo.
In Korean, "sister" is said as "언니" (eonni) when referring to an older sister and "여동생" (yeodongsaeng) for a younger sister. "Brother" is "형" (hyeong) when referring to an older brother and "남동생" (namdongsaeng) for a younger brother. These terms reflect the importance of age hierarchy in Korean culture.
여동생 = sister
It is Sister in Korean ^-^
How to say diana in korean
noona for elder sister 누나- that is how you right it
how do you say Braidyn in korean
Older sister coming from a female - "Eon-nie" Older sister coming from a male - "Noo-na" Younger sister coming from both gender - "Dong-saeng"
Will is 미래 in Korean.
If u mean how is it spelled in Korean, it's 여동생. 동생 means little brother (see there's no "여" which pretty much means female), but is often also used as little sibling. So the older brother would say that so and so is my 동생, regardless of the gender.
바쁘세요 = are you busy