In short

Korean has two words for “I” and you choose by politeness: 저 (jeo) in 해요체, 나 (na) in 반말. There is no usable everyday word for “you” - you address people by title (선생님 seonsaengnim), by name plus 씨 (민수 씨 Minsu ssi), or by a kinship term, and otherwise you just leave the pronoun out. And “my house” is normally 우리 집 (uri jip), literally “our house”.

The rule

Step 1 - pick the right “I” for your register. The polite set is 저 and the plain set is 나. They are not interchangeable: the pronoun has to match the sentence ending. 저는 학생이에요 (jeoneun haksaengieyo - I am a student) is consistent; *나는 학생이에요 mixes a casual pronoun with a polite ending, and *저는 학생이야 does the reverse. Both read as a mistake.

Step 2 - learn the contracted forms, because they are what you actually say. Both pronouns fuse with the subject particle 가 and with the possessive 의:

• 저 + 가 -> 제가 (jega). Never *저가.
• 저 + 의 -> 제 (je) = “my”. 저의 exists in writing but sounds stiff.
• 나 + 가 -> 내가 (naega). Never *나가 (that is the verb “go out”).
• 나 + 의 -> 내 (nae) = “my”.
• With 은/는 and 을/를 there is no fusion: 저는, 저를 / 나는, 나를 (colloquially shortened to 절, 날).

Step 3 - use 우리 where English uses “my”. With nouns naming something you share with a group - family, home, workplace, school, country - Korean prefers 우리 (uri, “our”): 우리 집 (uri jip - my/our house), 우리 엄마 (uri eomma - my mum), 우리 회사 (uri hoesa - my company), 우리 학교 (uri hakgyo - my school). 제 집 is not ungrammatical, but it sounds oddly proprietary. The humble equivalent, used when you are speaking to a customer or a superior about your own side, is 저희 (jeohui): 저희 회사 (jeohui hoesa - our company). Note the spacing: 우리 집 and 우리 엄마 take a space, but 우리나라 (urinara - our country) is written as one word.

Step 4 - do not say 당신. 당신 (dangsin) is a textbook translation of “you” and a trap. In real speech it is used between spouses, in song lyrics and prayers, or aggressively during an argument. Instead, in order of preference:

1. 직함 + 님 for anyone with a role or rank: 선생님 (seonsaengnim - teacher), 사장님 (sajangnim - company president), 과장님 (gwajangnim - section manager). This is the safest default for a superior.
2. 이름 + 씨 for a peer or a colleague whose name you know: 민수 씨 (Minsu ssi). Attach 씨 to the given name or the full name, never to the family name alone. Never use 씨 upward to a boss or a teacher.
3. Kinship terms, extended to non-relatives: a woman says 언니 (eonni) / 오빠 (oppa) to an older woman / man; a man says 누나 (nuna) / 형 (hyeong). 이모 (imo - aunt) is common for an older woman running a restaurant.
4. Omit it. Korean drops any pronoun the context supplies. 어디에 가요? (Eodie gayo?) already means “where are you going?”.

너 (neo) is the genuine second-person pronoun, but it is 반말 only - for close friends, children and juniors. Its subject form is irregular: 네가 (nega), which almost everyone pronounces and often writes as 니가 (niga) to keep it distinct from 내가. Possessive is 네 (ne), plural 너희 (neohui).

Step 5 - for “he/she”, use a noun phrase. 그 (geu) and 그녀 (geunyeo) are a written-language calque invented to translate European novels. 그녀 in particular is essentially never spoken. Say 그 사람 (geu saram - that person) normally, 그분 (geubun, one word) politely, or just repeat the name or the title. 분 is what makes 그분 polite: it is a bound noun meaning “person”, so it never stands bare but leans on whatever precedes it - a demonstrative (그분), 여러 (여러분), a number in place of 명 (한 분, han bun - one person), or a modifier clause (lesson 24). Its plural is 분들 (bundeul).

Step 6 - the plural -들 is optional. -들 (-deul) marks a plural but is not required, and is mostly used with people or with a specific known group: 학생들 (haksaengdeul - the students). Drop it after a number: 학생 세 명 (haksaeng se myeong - three students), not *학생들 세 명.

Forms & patterns

The first-person paradigm - the row you choose is decided by the sentence ending:

Second person - what to say instead of a pronoun:

Third person - written form vs what people actually say:

Examples

Common mistakes

• 저가 할게요. -> 제가 할게요. (Jega halgeyo.) - 저 does not simply take 가; 저 + 가 contracts to 제가. The same holds for 나 + 가 -> 내가.
• 나는 김민수예요. -> 저는 김민수예요. (Jeoneun Gim Minsuyeyo.) - the pronoun must match the ending. 나 belongs with 반말 (나는 김민수야), 저 with 해요체.
• 당신은 어디에 가요? -> 민수 씨는 어디에 가요? (Minsu ssineun eodie gayo?) - 당신 is not a neutral “you”. Use name + 씨, a title + 님, or drop the pronoun entirely.
• 그녀는 제 친구예요. -> 그 사람은 제 친구예요. (Geu sarameun je chinguyeyo.) - 그녀 is a written-language form. In speech say 그 사람 or, politely, 그분.
• 제 집은 서울에 있어요. -> 우리 집은 서울에 있어요. (Uri jibeun Seoure isseoyo.) - for home, family, school and workplace Korean says 우리, even when only one person is meant.

Tips

• Two things move together: 저 / 제가 / 저희 go with -요 endings, 나 / 내가 / 우리 go with 반말. If you catch yourself saying 저 in one sentence and 내가 in the next, one of them is wrong.
• 저희 is humble, so it excludes the listener. Speaking to your own team you say 우리; speaking to a client about your team you say 저희. One fixed exception: your own country is always 우리나라 (urinara), never 저희 나라 - it is odd to be humble about a nation.
• A useful reflex: when in doubt, drop the pronoun. Korean sentences with no subject at all are completely normal, and omission can never be rude - whereas guessing at a form of address can.
• Two look-alikes worth knowing early. 자기 (jagi) is “oneself” in writing, but in conversation it is what couples call each other (“honey”) - do not use it as a general “you”. 본인 (bonin - the person in question, oneself) is formal and appears on forms and in official speech.