How should you speak to someone you don’t know? Korean normally use family titles to refer to non-family and Koreans rarely use the term you as we have seen in Meeting A Korean For The First Time, so, should you just roughly guess someone’s age and call all older people 할머니 (grandmother) or 할아버지 (grandfather), all middle aged people 아줌마 (aunt/ma’am) or 아저씨 (mister/uncle) and all young people 학생 (student)? The answer is no. This is one of Korean culture to show respect.
How should you speak to a stranger?
If you should need to speak to a stranger in a public place, such as the street or subway, it’s best to address him indirectly and avoid guessing an appropriate title. Begin with 저 or 저기요 to attract the person’s attention and once you have the person’s attention, you may begin speaking. Use it like English word – Excuse me. For examples, 저/저기요, 이 근처에 화장실 있어요? – Excuse me, is there a bathroom near here?
In a restaurant, however, get your server’s attention by waving your hand and saying 여기요. This method works for flagging a taxi as well. In these cases, it’s fine to speak loudly to make sure you get the waiter or taxi driver attention. But otherwise, stick with 저기요 for strangers. This way you can avoid all of those problematic titles!