"...이랑 ..."이 무슨 뜻인지 설명 부탁 합니다.
This is a pattern I've been bleeping over for a long time, sort of understanding, but not really confident I understand it. Please explain the usage of 이랑 to me.

Example:

너 혼자 가지말고 친구들이랑 같이 가라.

감사합니다.

Question

"...이랑 ..."이 무슨 뜻인지 설명 부탁 합니다.
This is a pattern I've been bleeping over for a long time, sort of understanding, but not really confident I understand it. Please explain the usage of 이랑 to me.

Example:

너 혼자 가지말고 친구들이랑 같이 가라.

감사합니다.

Answer

"Noun + -(이)랑" is the casual form of "과" or "와" meaning "with".:)
"이" can be added when the noun has the final consonant(=받침).

e.g. 
친구들 + 이랑 ('들' has the final consonant  'ㄹ')
= 친구들 + 과
친구랑
= 친구 + 와

\^o^/