-부터 and -까지 mean “from/since” and “to/until” respectively, and they can be used when referring to location or time.
They attach to nouns just as they are, regardless of whether they end in a consonant or a vowel.
War of Hormone:
머리부터 발끝까지 최고 최고 ~ “From your head to your toes you’re the best. The best.”
Original nouns: 머리 – head & 발끝 – the ends of one’s feet
예전부터 날 무시했던 친구들 ~ “The friends who’ve ignored me since before.”
Original noun: 예전 – before
Attack on Bangtan:
데뷔부터 지금까지 쭉 위로 ~ “From debut until now, straight upward.”
Original nouns: 데뷔 – debut & 지금 – now
해가 뜰 때까지 where the party at? ~ “Until the sun comes up, where the party at?”
Original noun: 때 – the point in time when something happens
-까지 can also be used to mean, “even to the extent of X”.
내 아픈 상처까지 네게 다 들키진 않을까? ~ “Even my hurting wounds have all been exposed to you, haven’t they?”
Here -까지 is attached to the word 상처 (wounds). So the meaning is like, “Everything, right up to my wounds even, has been exposed.”
You can say “How long has X been happening?” by combining “언제” (when) with -부터. The literal meaning, of course, is “from when?”
Promise (by Jimin):
언제부터 넌 날 아프게 했던가? ~ “How long have you been hurting me?”
You can also add -까지 to 언제 to mean “for how long?” (literally “until when”). I can’t find a BTS example, but the principle is exactly the same.