우리 means "we" or "our" 내 means "my" Quoted from http://www.learnkoreanlp.com/2006/12/possessive-forms.html 나의 = my (informal) = 내 (short) 저의 = my (polite)= 제 (short) 우리 = our (informal) 저희 = our (polite) Therefore, 저희 아버지 means "our father" However, in Korean, people usually say 저희 아버지 rather than 제 아버지. It is a cultural thing. Koreans usually say 우리 아빠, 우리 엄마, 저희 아버지, 저희 어머니 rather than 내 엄마, 내 아빠, 제 아버지 or 제 어머니. I believe it is due to the distinct "group mindset" of Korean culture. So when you want to say "my mum", you wouldn't say 내 엄마 or 제 어머니 but rather 우리 엄마 or 저희 어머니. Therefore, although 우리 아들이에요 means "our son", you'd still say 우리 아들이에요 when you're talking about "my son." I think this use of "our" usually occurs when referring to a family member or any other group-ish things. For example, 우리 아빠 (or 저희 아버지) = our dad (our father) rather than 내 아빠 or 제 아버지 우리 엄마 = our mum (my mum) 우리 아들 = our son (my son) 우리 딸 = our daughter (my daughter) 우리 나라 = 'Our country' (my contry) rather than 내 나라 우리 말 = 'our language' (my language) rather than 내 말 우리/저희 가족 = 'our family' (my family) 우리/저희 학교 = 'our school' (my school) 우리 집 = 'our house' (my house) rather than 내 집 우리 강아지 = our puppy (pet)

우리 means "we" or "our"(possessive). There's also the humble form 저희. 내 is a contraction of 나의 (나+의)("I/me"+"'s"[possessive]). It means "my". Due to Korean culture, to show respect, humility and a sense of community/nation, Koreans often use 우리 instead of 내/제 (depending on the situation). So it would literally be translated as "our" but the actual understood meaning is "my" (or "our" if you really meant it that way).