Saying good morning in Korean is very easy to learn and is one of the many greetings you should learn from the very beginning.
‘안녕하세요’ is the most common way people greet each other in the morning. You may know this phrase to mean ‘Hello’ in Korean, but this phrase is also used for most greetings in Korean.
좋은 아침 (jo-eun a-chim)
‘좋은 아침’ is also used, but less frequently compared to the former. ‘좋은’ literally means ‘good’ while ‘아침’ means ‘morning in Korean. If you use this to say good morning, you will be understood, but remember that 안녕하세요 is used much more often.
These two forms are the casual forms of good morning. If you want to be more formal, you can use phrases like:
좋은 아침입니다 = Good morning or literally the morning is good. The formal form of ‘좋은 아침’.
잘 주무셨어요? = Did you sleep well? (Used towards people older than you)
Other casual forms for use with friends:
잘 잤어? = Did you sleep well?
You can also feel free to write/text these in the morning to your friends or your significant other (especially ‘질 잤어?’).