Many languages (Spanish, Russian, and German to name a few) have different verb forms depending on whether you're addressing a peer or a superior.
Korean, like Japanese, raises this concept to an art form. There are several levels of politeness. The level you use is determined by the social relationship between you and the person you’re talking with. You signify the politeness level by the endings that you tack on to the verb stem.
The two main levels we will be concerned with are:
(There are other forms used when addressing intimate friends or children. We won’t worry about them.)
Stems & Pieces
Grammar Index