-nim: suffix denoting an additional level of respect

-ssi: honorific added at the end of a name to politely address someone who is of approximately equal speech level

Abeonim: father-in-law; can be used to address an older man who is like a father figure

Ahjumma: way to address an older woman who is not blood related, somewhat like calling them "aunt"

Ahjussi: way to address an older man who is not blood related, somewhat like calling them "uncle"

Aigoo: somewhat like a verbalized sigh; can be used to express various feelings (usually negative) like frustration, exhaustion, panic, annoyance etc.

Banmal: literally "half speak", it is an informal/familiar speech that requires fewer words to convey meaning; generally people of the same age, older, or familiar with you (like family members, significant others, etc.) can use banmal on you; the opposite is jondaemal which is formal speech

Dongsaeng: how one refers to someone younger; can be a sibling, a close friend, or in some cases just an acquaintance

Eomeonim: mother-in-law; can be used to address an older woman who is like a mother figure

Mehrong: word describing the action of sticking out your tongue in a teasing manner

Kimchi: fermented dish of various vegetables and seasonings

Oppa: how a female addresses an older male that she is comfortable with; usually used for an older brother, a close friend, or a boyfriend

Saranghae: I love you

Skinship: physical intimacy/touching

Sunbae: how one addresses another of a higher year or with more years of experience in a field; usually used in a school or work setting

Yah: literally "hey", but not like a greeting. It is an informal/impolite way to get someone's attention commonly used only between friends or on someone younger than you. Addressing an older person in this way is considered disrespectful.