안녕하세요. = Hello. / Hi. / How are you? 안녕 + 하세요 = 안녕하세요. an-nyeong + ha-se-yo = an-nyeong-ha-se-yo 안녕 = well-being, peace, health 하세요 = you do, do you? 안녕하세요 is the most common way of greeting someone in Korean and it is in formal or polite way. And when you say “Good-bye” in formal/polite Korean, there are two types of expressions, and both of these expressions have the word 안녕 an-nyeong. 1. If you are leaving, and the other person is staying, you can say: 안녕히 계세요. an-nyeong-hi gye-se-yo 2. If you are staying, an the other person is leaving, you can say: 안녕히 가세요. an-nyeong-hi ga-se-yo Hope it will help you =)

Just saying 안녕 (annyeong) is the most informal way of saying hello or goodbye. It's what you would say to your close friends, or to little kids. As you watch Korean dramas, you can listen and observe which form of "Hello" and "Goodbye" the actors use.

안녕하세요 & 잘가요