This was originally posted by DonnaIsHerName
Hi! Here are some general tips for speaking Korean. This post isn't for advanced grammar or things like that, but rather some things that you should know about the Korean language before you start learning it. Just fun facts 
HONORIFICS. This is probably one of the most important things about Korean, and it really tells you a lot about Korean culture and Confucianism. You can learn more about that in the my comment below! Koreans use different words and tones depending on who they are talking to. If they are talking to authority figures such as parents, older relatives, or teachers, they use honorifics. The same applies when they are talking to strangers or people they don't know very well. You can view this like 'sir' or 'ma'am' in English. -- Quick tip/ex: If you are thanking your friend, you would say 고마워 but to thank, say, your great-great-great grandfather, you would say 고맙습니다.--
"JINJJA?!" Koreans tend to use words like "jinjja 진짜" and "hul 헐 (note: I'm not sure if this is the correct way to write it in English)" to (usually) show astonishment or disbelief. Trust me on this. Literally half of my conversations consist of the word "hul".
GRAMMAR. When you are learning Korean, it is very, I repeat very, important to pay close attention to the spacing between letters. In English, spacing is relatively simple (I'm not saying that English is inferior to Korean just because it's easier; both languages are equally interesting and unique): WORD + space + WORD. For example, I + space + run. However, in Korean, it's a bit... more complex. Even Korean natives have trouble with that. I won't delve deep into that now, because there is so much to talk about. However, just keep that in mind while you are learning Korean and looking at example sentences.
HOW TO LEARN KOREAN FAST. Well, to be honest, you should practice, practice, practice. But if you're a Korean intermediate and you want to speak at a conversational level like a Korean native, I suggest you listen to K-Pop (BTS, NCT, Blackpink, ITZY... There are so many options) or watch some K-Drama (or you can watch web dramas on YouTube.
I know this was not a very helpful post, so as a final note, you can comment on this post on some Korean phrases or sentences that you think sounds awkward and I can give you some suggestions on how to fix them to sound more natural. You can also ask me about Korean culture if you are planning to move to Korea or you want to write a K-Pop fanfic or whatever.
You're welcome to comment anytime 
I wish you the best of luck on learning the Korean language!