North–South differences in the Korean language

The Korean language has diverged between North and South Korea due to the length of time that the two states have been separated.

The Korean Language Society in 1933 made the "Proposal for Unified Korean Orthography" (Korean: 한글 맞춤법 통일안; Hanja: 한글맞춤法統一案; RR: Hangeul Matchumbeop Tong-iran). But with the establishments of the Democratic People's Republic of Korea and the Republic of Korea in 1948, the two states have taken on differing policies regarding the language.

Researching language differences between North and South Korea has been challenging, and there have been reports of inaccurate results. It is hard to know how North Koreans use their standard language because North Korean defectors often speak a dialect rather than the standard language. Some scholars argue that North Korean propaganda and the South's over-interpretation of it contributes to the confusion regarding the North Korean standard language. North Korean propaganda has characterized its language as being "pure", contrary to South Korea's.

North Korea states its standard language as the language of Pyongyang. However, South Korean scholars have claimed it is more similar to the pre-divided Seoul dialect than the pre-divided Pyongyang dialect, and suggested that its pronunciation and grammar are based on the Seoul area rather than the Pyongyang area.

In some cases, South Korean schools have taught North Korean purified words that are not actually used in North Korea, leading to disputes in South Korea over whether a North Korean defector actually uses the word in North Korea. Some scholars have also doubted a study that found that the most common loan words in North Korea were not Russian loanwords but English loanwords.