Korean pronouns pose some difficulty to speakers of English due to their complexity. The Korean language makes extensive use of speech levels and honorifics in its grammar, and Korean pronouns also change depending on the social distinction between the speaker and the person or persons spoken to.
In general, Koreans avoid using second person singular pronouns, especially when using honorific forms.
Overview of pronouns 
|First person||저 (jeo), 나 (na)||저희 (jeohui), 우리 (uri)|
|Second person||당신 (dangsin), 너 (neo)||당신들 (dangsindeul), 너희 (neohui)|
|Third person||그, 그녀(f) (geu/geunnyeo)||그들, 그녀들 (f) (geudeul/geunnyeodeul)|
For each pronoun there is a humble/honorific and an informal form for first and second person. In the above table the first pronoun given is the humble one, which one would use when speaking to someone older or of high social status. Note that dangsin (당신) is also sometimes used as the Korean equivalent of "dear" as a form of address. Also, whereas uses of other humble forms are straightforward, dangsin must be used only in specific social contexts, such as between two married couples. In that way it can be used in an ironic sense when used between strangers, usually during arguments and confrontations. It is worth noting that dangsin is also an honorific third-person pronoun, used to refer to one's social superior who is not present.
There are two third person pronouns, male and female; however, the female form sounds awkward (due to its similarities with a bad word, 그년), and is mostly used when translating texts from other languages. Korean originally had only a gender-neutral third person pronoun, geu (그), which could mean she or he. However it has increasingly been interpreted as a "male" pronoun used for both genders. Although in recent years the pronoun geunnyeo (그녀) is slowly gaining ground as a female counterpart due to the influence of translations from European languages, it is almost restricted to specific styles of written language, because Korean generally uses subjectless or modifier+noun constructions.
Pronouns in detail 
Korean has personal pronouns for the 1st and 2nd person, with distinctions for honorifics, and prefers demonstrative pronouns in the 3rd person, which make a three-way distinction between close, distant, and previously mentioned.
|1st person familiar||나 (na)||우리 (uri)
|2nd person familiar||너 (neo)||너희 (neohui)
|3rd person familiar||그 (geu)||그들 (geudeul)|
|1st person humble||저 (jeo)||저희 (jeohui)
|2nd/3rd person respectful||(see below)|
The plural suffix -deul is also used with pronouns, both where it's necessary, as in geudeul (그들, "they") and optionally in some cases like urideul (우리들) where it's redundant.
Geu (그) has a range of meanings, "he," "she," or "it." Due to this ambiguity and the ability of the Korean language to drop pronouns which can be reconstructed from context, geu is seldom used by itself. But it has enjoyed a revival recently as the translation of "he" in works translated from European languages.
The monosyllabic pronouns na (나), neo (너), and jeo (저), add -i (이) or -i ga (이가) rather than the expected -ga (가) to form the nominative case (see below). This produces the forms nae (내), ne (네), and je (제). Geu (그) is found in all three forms, as geu-i (그이) and geu-iga 그이가, in addition to regularly formed geuga (그가).
Additionally, because many Koreans have lost the distinction between the vowels ae (애) and e (에), ne (네, "you") is dissimilating to ni (니).
In colloquial Korean, the topic forms naneun (나는, "me") and neoneun (너는, "you") are often pronounced, and sometimes written, as nan (난, "me") and neon (넌, "you"). Similarly, the accusative forms nareul (나를) and neoreul (너를) tend to become nal (날) and neol (널). The possessives na-ui (나의, "my") and neo-ui (너의, "your") have the alternate forms nae (내) and ne (네).
The classifier jjog (쪽, "side") is also used when referring to people. Ijjog (이쪽, "this side") then means "this person, these people" (that is, he, she, or they), but is further extended via "our side" as a polite form for "us" or "me".
|Near||i- 이||igeos 이것 "this"||igos 이곳, yeogi 여기 "here"|
|Given||geu- 그||geugeos 그것 "that"||geogi 거기 "there"|
|Far||jeo- 저||jeogeos 저것 "that"||jeogi 저기 "yonder"|
|Which?||eoneu 어느||mueos 무엇 "what?"||eodi 어디 "where?"|
The "given" series is often called "medial", and said to be close to the addressee rather than the speaker. However, they actually refer to referents already established in the conversation, whether near or far. With new referents, the near or far forms will be used.
In colloquial speech, the object words, composed of the prefix plus the generic noun classifier geos (것), frequently drop the final s (pronounced t), with proximate igeos (이것) becoming igeo (이거) This occurs before case clitics as well, with the nominative form igeos-i (이것이) becoming ige (이게), topical igeos-eun (이것은) becoming igeon (이건), and accusative igeos-eul (이것을) becoming igeol (이걸, "this").
In colloquial Korean, interrogative mu-eos (무엇) contracts to mwo (뭐, "what") (often pronounced meo, as w tends to drop after m), and the accusative mu-eos-eul (무엇을) contracts to mwol (뭘, "what").
The word for "who" is nugu (누구), which in the nominative is nuga (누가). "How many" is myeoch (몇).
Second person reference 
Korean has a tu-vous distinction in the second person. Neo (너) is the pronoun corresponding to French tu, but instead of a single equivalent to vous, a variety of strategies are used. More specifically:
- Leaving out the subject of the sentence if it can be implied by the context. In English, sentences need explicit subjects, but this is not so in conversational Korean.
- Using the person's name when talking to someone younger than yourself. With people older than you, it is custom to use either a title or kinship term (see next point).
- Using a kinship term: 언니 (eonni, "older sister" if speaker is female), 누나 (nuna, "older sister" if speaker is male), 오빠 (oppa, "older brother" if speaker is female), 형 (hyeong, "older brother" if speaker is male), 아줌마 (ajumma, "middle aged woman"), 아주머니 (ajumeoni, also "middle aged woman" but more polite), 아저씨 (ajeossi, "middle aged man"), 할머니 (halmeoni, "grandmother") of 할아버지 (harabeoji, "grandfather"). In Korea it is common to use kinship terms for people who are not family at all. The term 아가씨 (agassi, "young lady") is preferable when addressing a young girl of unknown age. It is mostly seen used in public places like restaurants. But it will also sometimes be used by men in pick-up lines. By definition, the actual difference between 아가씨 and 아줌마 reside in marriage status and not age.
- Using the appropriate title, usually ending in -nim e.g. seonsaengnim ( 선생님, "teacher", although it is also often used as a general honorific term for other professions like managers etc.) or gwajangnim (과장님 "director"), etc.
- Using the plural yeoreobun (여러분, "ladies and gentlemen") where applicable.
If none of these are possible, an honorific common noun, e.g. dangsin (당신, "said body") or jane (자네, "oneself") (used for "you" in the familiar speech level). The pseudo-pronoun dangsin is actually a noun, from the Sino-Korean loanword 當身 "the aforementioned body". There are a large number of such pseudo-pronouns in Korean.
These methods are ambiguous, that is, they can indicate a third person as well as a second person. In order for an honorific noun to be interpreted as a second person pronoun, it must agree with the speech level of the verb - that is, the level of respect used must be consistent throughout the sentence. Korean verbs reflect the social status of the person being spoken to, so if that same person or group of people listening is also mentioned in the sentence, neither reference should be higher than the other. A lowly noun used with a high speech level, or an honorific noun used with a low speech level, can only be interpreted as a third person pronoun.
For example, jane is used for "you" in the familiar speech level, and is appropriate only as long as the familiar speech level itself is. The familiar speech level is used to talk in a friendly way to close friends and family who are younger or subordinate. In situations where that speech level would be inappropriate or insulting, jane is too.
Even when the pronoun used and the speech level agree, there is still some possible ambiguity, but this can be resolved by context.
See also 
- Dong Jae Lee. Some Problems in Learning Korean Second-Person Pronouns, in The Korean Language: Its Structure and Social Projection, Ho-min Sohn, editor. Hawaii: University of Hawaii, c1975.