Apologizing is a very important skill in life, even more so in a language you don't know well. You are likely to make idiomatic or cultural mistakes if you are a tourist or have no experience in the language. Follow the steps below to apologize in Korean!
Steps

Step 1. Learn a bit of the language first
The grammar is very similar to the grammar of Spanish and the subject of the sentence is sometimes implicit rather than stated.
You don't need to learn Hangul, the Korean alphabet, if you are visiting the country for a short period of time, but if you want to speak it fluently, you should. In fact, learning to read Hangul can be a quick and easy process, some say it only takes a few hours

Step 2. Understand the difference between formal and informal speech
The informal is the one used with family, friends and people your age or younger.
- If in doubt, use the formal way to address someone else. People will be more upset if you address yourself informally when the situation calls for a certain courtesy.
- This way of speaking is not only limited to Korean, but is also used in French, Italian, and German, to name a few.
Method 1 of 2: Talk Informally

Step 1. Say "미안해"
It is pronounced "Mi-an-e" and means "I'm sorry." It is an informal phrase and is used with friends or people younger than you.
Method 2 of 2: Talk formally or with an older person

Step 1. Say "미안 해요"
It means "I'm sorry" and is pronounced "Mi-an-e-io". It is a formal phrase and is used with people you do not know well, with someone older or with someone in a higher hierarchy.

Step 2. Say "미안 합니다" which means "sorry"
This is a very formal and courteous way of apologizing. It is pronounced "Mi-an-ap-ni-da". It can be used with someone you don't know well, someone older or more senior.