McCune–Reischauer romanization is one of two most widely-used Korean language romanization systems, along with the Revised Romanization of Korean, which replaced (a modified) McCune–Reischauer as the official romanization system in South Korea in 2000. Another variant of McCune–Reischauer is used as the official system in North Korea.
The system was created in 1937 by two Americans, George M. McCune and Edwin O. Reischauer. With a few exceptions, it does not attempt to transliterate Korean text but rather to represent the phonetic pronunciation. McCune–Reischauer is widely used outside of Korea. A variant of it was used as the official romanization system in South Korea from 1984 to 2000. A third system — the Yale Romanization system, which is a transliteration system — exists, but is used only in academic literature, especially in linguistics. During the period of Russian interest in Korea at the beginning of the 20th century, attempts were also made at representing Korean in Cyrillic.
Characteristics and criticism 
The McCune–Reischauer system is friendly to westerners.[according to whom?] For example, Korean has phonologically no distinction between voiced and voiceless consonants, but it phonetically distinguishes them. Aspirated consonants like "p' ", "k' ", and "t' " are distinguished by apostrophe from unaspirated ones, which may be falsely understood as a separator between syllables (as in 뒤차기 → twich'agi, which consists of the syllables twi, ch'a and gi). The apostrophe is also used to mark transcriptions of ㄴㄱ as opposed to ㅇㅇ: 잔금 → chan'gŭm vs. 장음 → changŭm).
Critics[who?] of the McCune–Reischauer system claim that casual users of the system omit the breves ( ˘ ) over the o for 어 and the u for 으, because typing o or u without the breves is often easier than adding them. This, in turn, can lead to confusion over whether the o being Romanized is 오 or 어 or the u being Romanized is 우 or 으. Casual users also often omit the apostrophe that differentiates aspirated consonants (ㅋ, ㅌ, ㅍ, and ㅊ) from their unaspirated counterparts (ㄱ, ㄷ, ㅂ, and ㅈ), which can also lead to confusion. Defenders[who?] of the McCune–Reischauer system, however, respond that a casual user unfamiliar with Korean can easily approximate the actual pronunciation of Korean names or words even when breves and apostrophes are omitted, although it is still best to include them.
Such common omissions were the primary reason the South Korean government adopted a revised system of romanization in 2000. Critics of the revised system claim it fails to represent 어 and 으 in an easily recognizable way, and that it misrepresents the unaspirated consonants as they are actually pronounced.
Meanwhile, despite official adoption of the new system in South Korea, many in the Korean Studies community – both in and out of South Korea – and international geographic and cartographic conventions generally continue to use either the McCune–Reischauer or Yale system, and North Korea uses a version of McCune–Reischauer. Even within South Korea, usage of the new system is less than universal, as was the case with the variant of McCune–Reischauer that was the official Romanization system between 1984/1988 and 2000.
This is a simplified guide for the McCune–Reischauer system. It is very useful for the transliteration of names but will not convert every word properly, as several Korean letters are pronounced differently depending on their position.
!Romanization |a||ae||ya||yae||ŏ||e*||yŏ||ye||o||wa||wae||oe||yo||u||wŏ||we||wi||yu||ŭ||ŭi||i |}
- * e – written as ë after ㅏ and ㅗ
- The consonants digraphs (ㄳ, ㄵ, ㄶ, ㄺ, ㄻ, ㄼ, ㄽ, ㄾ, ㄿ, ㅀ, ㅄ) only exist in finals. These digraphs are transcribed by their actual pronunciation.
|Initial consonant of the next syllable|
† An initial consonant before a vowel to indicate absence of sound.
Basically, when deciding whether g or k, b or p, d or t and j or ch is used, use g, b, d or j if it is voiced, and k, p, t or ch if it is not. Pronunciations such as these take precedence over the rules in the table above.
North Korean variant 
In North Korea's variant of McCune–Reischauer, aspirated consonants are not represented by an apostrophe, but instead by adding an "h". For example, 평안 is written as Phyŏngan. With the original system this would be written as P'yŏngan.
South Korean variant 
In South Korea's variant of McCune–Reischauer, in official use from 1984 to 2000, 시 is written as shi instead of the original system's si, and others like 샤, 셔 and so on, where the pronunciation is deemed closer to a /ʃ/ sound than a /s/ sound, are romanised with sh instead of s. The original system deploys sh only in the combination 쉬, as shwi.
ㅝ is written as wo instead of the original system's wŏ in this variant. Because the diphthong w (ㅗ or ㅜ as a semivowel) + o (ㅗ) does not exist in Korean phonology, the South Korean government omitted a breve in wŏ.
Hyphens are used to distinguish between ㄴㄱ and ㅇㅇ in this variant system, instead of the apostrophes in the original version. Therefore, apostrophes are used only for aspiration marks in the South Korean system.
Additionally, assimilation-induced aspiration by an initial ㅎ is indicated, e.g. 직할시 (直轄市; "a directly-governed city") is written as chik'alshi, which under the official system is chikhalsi.
See also 
- 직할시 (jikhalsi in the Revised Romanization) is one of a former administrative divisions in South Korea, and one of a present administrative divisions of North Korea. In 1995, it was replaced by 광역시 (廣域市; gwang-yeoksi; "metropolitan city") in South Korea.
- Korean McCune–Reischauer Romanization Dictionary
- A Practical Guide to McCune–Reischauer Romanization: Rules, guidelines, and font
- Comparison table of different romanization systems from UN Working Group on Romanization Systems (PDF file)
- PDF files of the
- Romanization System of Korean: McCune Reischauer (with minor modifications) BGN/PCGN 1945 Agreement
- Online tool for McCune–Reischauer romanization (with BGN modifications)