What's the difference between ㄹ게요 and ㄹ께요? I've been wondering about this for a while now. According to what I learned, ㄹ게요 is used when we talk about a prediction, a plan or even an unconfirmed "truth". And ㄹ께요 is used to express a promise, a well-thought plan, it shows the sureness of the speaker. But as for this sentence "항상 응원해 줄게요" - I will always support you. I think that it would be better if we use ㄹ께요 instead of ㄹ게요 cause... well, the sureness. But I have never seen people use ㄹ께요 in this case, and it kinda makes me wonder a lot. It would be great if someone can help me understand more about these two grammars, thank you ^^

What does 돌려막기 means? I googled but still the meaning is not very clear to me. Can someone explain to me please? :<

What does 얜나 means? I saw these phrase: 얜나처럼 and 얜나한테 online but it seems like 얜나 isn't a word cause I can't look it up in dictionary

What is the difference between 처음 뵙겠습니다 and 반갑습니다? I still these two phrases are different in some way. Please help me differentiate, if there's any difference