You can now watch Lesson 3 of my newest free course, "Master Politeness Levels." This course covers everything about politeness levels you will need in order to speak Korean more naturally and understand it like a native. You'll learn about the important speech levels, as well as how they're used together.
Note that YouTube Members also get access to watch this series several lessons in advance. You can find a link to the playlist for the course in the video description.