Formal:
* 안녕하세요, 여러분 (Annyeonghaseyo, yeoreobun): This is the most common and polite way to greet everyone. It's suitable for formal settings or when you're speaking to people you don't know well.
Informal:
* 안녕하세요, 다들 (Annyeonghaseyo, daddeul): This is a slightly more informal way to say hello to everyone. It's appropriate for casual settings or when you're speaking to friends.
* 안녕, 다들 (Annyeong, daddeul): This is a very informal way to say hello to everyone. It's only appropriate for close friends or family.
More casual and playful:
* 모두 안녕 (Modu annyeong): This literally translates to "Everyone, hello" and is a more casual and playful way to greet everyone.
It's always a good idea to consider the context and your relationship with the people you're speaking to before choosing which greeting to use.