I'm native English (British) but was raised in France so my spoken French is mostly indistinguishable from native French speakers. I also studied Korean, Japanese, Mandarin Chinese, German and Welsh to varying degrees of proficiency.
I mostly use the Korean because one of the characters is half Korean and leaves himself sticky notes on his desk or writes his diary in Korean just for some visual worldbuilding and an easter egg for anyone who can read it. I also have a French version of my comic and almost all characters are canonically French or part French.
To answer your question it depends on the level of closeness to your relative. Korean words for family members seem more complicated than in English because they're more or less saying what they are in shortened form so it's clear who you are blood related to and who's married into the family.
If your mother has a sister who is married, your aunt is 이모 (imo) and your uncle is 이모부 (imobu, litterally "spouse of imo").
If your mother has a brother who is married, your uncle is 삼촌 or 외삼촌(samchon or oesamchon, which sort of means "three degrees of separation", the oe- being a prefix meaning "outside of" and is used for the mother's side of the family who were traditionally considered not a full part of the family) and your aunt is 외숙모 (oesukmo).
You can also use the word 숙모 (sukmo) for any aunt in Korean if I'm not mistaken, I've heard it used for both.