McCune–Reischauer romanization () is one of the two most widely used Korean language romanization systems. A modified version of McCune–Reischauer was the official romanization system in South Korea until 2000, when it was replaced by the Revised Romanization of Korean system. A variant of McCune–Reischauer is still used as the official system in North Korea. 

The system was created in 1937 by George M. McCune and Edwin O. Reischauer. With a few exceptions, it attempts not to transliterate Korean hangul but to represent the phonetic pronunciation. McCune–Reischauer is widely used outside Korea. 

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 → "twich'agi", which consists of the syllables "twi", "ch'a" and "gi"). The apostrophe is also used to mark transcriptions of ("n'g") as opposed to ("ng"): → "chan'gŭm" vs. → "changŭm"). 

Critics of the McCune–Reischauer system claim that casual users of the system omit the breves ( ˘ ) over the "o" for and the "u" for because typing "o" or "u" without the breves is often easier than adding them. That can lead to confusion over whether the "o" being romanized is or or the "u" being Romanized is or . Casual users also often omit the apostrophe that differentiates aspirated consonants (, , , and ) from their unaspirated counterparts (, , , and ), which can also lead to confusion.
How many romanization systems does Korea predominately use?
Which is the official system?
Who created the McCune-Reischauer system?
Did he have help?
From who?
What year was it created?
How long was it the official South Korean system?
In what country is a variant of the original still the official system?
Is used elsewhere, also?
Does it attempt to translate characters, or sound them out?
What do casual users sometime leave out?
What punctuation is used to separate aspirated and non-aspirated consonants?
What can it be mistaken for?
What are a few consonants that use this puncuation?
Two.
two 
The Revised Romanization of Korean system
the Revised Romanization of Korean system
George M. McCune.
George M. McCune
Yes.
and Edwin O. Reischauer
Edwin O. Reischauer.
Edwin O. Reischauer. 
1937 .
1937 
Until 2000.
until 2000
North Korea.
 North Korea. 
Yes.
McCune–Reischauer is widely used outside Korea. 
Sound them out.
not to transliterate Korean hangul but to represent the phonetic pronunciation
The apostrophe.
the apostrophe
The apostrophe.
the apostrophe
A separator between syllables.
 as a separator between syllables
"P'", "k'", and "t."
"p'", "k'", and "t'