You: Informal: Singular is 너 and plural is 너희 Formal: The formal singular form of "you" is rarely used, and instead someone's title will be used, for example 선생님 or 장학사님 (supervisor). You can also use 여러분, which means something like "ladies and gentlemen," for a plural polite form of you. If you don't know someone's title (like a stranger), you can call them 아저씨 (for a man), 아줌마 (for a middle-aged woman), 아가씨 (for young women), and 할머니/할아버지 (for an old woman/man). There are also a lot of other possibilities for talking to people you are close to (relatives, friends, etc.). Korean people don't use second-person pronouns as much as English-speakers do. For he/she, you can use 그. "They" can be made by adding the plural particle to the end, so 그들.