안녕하세요 – Hello (polite) annyeonghaseyo
고마워요 – Thanks (polite casual) gomawoyo
감사합니다 - Thanks (formal) gamsahamnida
선생님 – Teacher seonsaengnim
형 – Older bro (boy → boy) hyeong
오빠 – Older bro (girl → boy) oppa
누나 – Older sis (boy → girl) nuna
언니 – Older sis (girl → girl) eonni