오빠, 언니, 동생 I understand that 오빠 is for a girl calling an older brother and that 언니 is a girl calling an older sister and 동생 is for either younger brother or sisters but if you were born in the same year, how many months apart would you have to be to call an older brother/sister 오빠/언니. Same goes for younger brother or sister too. Thank you!

What is the difference? What is the difference between: 어디에 있어요? AND 어디에 요? 감사합니다

How, when and where do you use/put in Korean Particles 은/는 and 이/가? I don't quite understand the difference between the two, How you actually use it, When do you use it and what the sentence may mean after the particles are put in...