Comparison of Japanese and Korean

Korean and Japanese both have an agglutinative morphology in which verbs may function as prefixes[13] and a subject–object–verb (SOV) typology.[14][15][16] They are both topic-prominent, null-subject languages. Both languages extensively utilize turning nouns into verbs via the "to do" helper verbs (する and 하다).

Modern Korean and Japanese share a similar system of proximal and distal demonstrative pronouns: i- (이), ku- (그) and jeo- (저) for Korean corresponding to the Japanese ko- (こ), so- (そ) and a- (あ) ("this", "that" and "that over there"). They both lack a compulsory distinction of plurality (for example "an apple" vs "apples" is usually not specifically distinguished).

Korean and Japanese also share the particle system. Korean and the Japonic languages are among the few extant languages in the world with topic markers. This allows words of different parts of speech to be placed in exactly the same order if some sentences are translated from one language to another. Such direct word for word swapping cannot be so easily done with any other languages, showing that Korean and Japanese are grammatically quite similar.

There are some differences, however. Japanese utilizes passive grammar more frequently than Korean, and has four common verb conjugations to express "if" (〜ならば、〜ば、〜たら、〜と), while Korean has three (-면/-으면, -라면/-이라면, -다면). Korean also has distinct future tenses (-겠- , -ㄹ/-을) while Japanese often relies on context rather than directly indicating the future nature of a sentence.

The two languages have previously been thought to not share any cognates (other than loanwords),[4] for their vocabularies do not phonetically resemble each other. However, a 2016 paper proposing a common lineage between Korean and Japanese traces around 500 core words thought to share a common origin.[17] Most resembling lexicon in the study has been observed between Middle Korean (15th century) and earlier Old Japanese (8th century), some of which is shown in the following table:

Although fewer in number, there have been also comparisons between stages other than Old Japanese and Middle Korean:

In addition to the above, there may be a relation between the words for morning (朝, asa; 아침, achim). A historical variant in Korean may have been pronounced "asa" (see: Asadal). There is also a minority theory attributing the name of the city Nara to a loanword from Korean (see: Nara, Nara#Etymology).

Phonetically, Korean and Japanese have a similarly limited inventory of vowel sounds, and both Japanese and old Korean (and some dialects of Korean) make use of vowel length.

Korean particles and polite grammatical ending conjugations can sometimes share a superficial similarity with Japanese. The Japanese particle が (ga) is similar to the particle 가 (ka) in function and sound. The informal and impolite conjugation of Korean's Copula 야 (ya) is similar to the dialectal informal copula や (ya) in Japanese (corresponding to だ in standardized Japanese).

Functionally, some peculiar aspects of particles and particle usage are also the same in both languages. For example, the particles 도 (*do*) and も (*mo*) not only share an inclusive function (similar to "too" in English), they also both function to emphasize sheer lack in negative sentences, or sheer intensity in positive sentences. 에 (e) and へ (he) have similar sounds, and one of 에's usages is similar to へ. Particles are also used in the same way to form basic vocabulary words. I.e., 도 (do) and も (mo) in the words for *no one* (아무도, 誰も), and the similar sounding 가 (ga) and か (ka) particle sometimes adding an unknown/questioning element to a word to form the equivalent meaning to English *some*, (i.e. in 뭔가 and 何か, meaning *something*).

However, some percentage of vocabulary in any language may be expected to resemble vocabulary in any other language to a certain extent through random coincidence. The likelihood that a word in one language will be perceived as resembling a word in another language is inversely correlated with the number of phonemes in the word (i.e. the shorter a word is, the more likely it will randomly resemble a short word in another language) and positively correlated with the degree of overlap in the languages' phonological systems (i.e. the more similar the sound systems of the two languages, the more likely it is that any word from one language will be perceived as sounding similar to a word from the other language).

Both languages use, to some extent, a combination of native scripts and Chinese characters.

Korean is mostly written in the Korean featural alphabet (known as Hangul in South Korea and Chosŏn'gŭl in North Korea). The traditional hanja (Chinese characters adapted for Korean) are sometimes used in South Korea, but only for specific purposes such as to clarify homophones (especially in TV show subtitles), linguistic or historic study, artistic expression, legal documents, and newspapers. Native Korean words do not use hanja anymore. In North Korea, the hanja have been largely suppressed in an attempt to remove Sinic influence, although they are still used in some cases and the number of hanja taught in North Korean schools is greater than that of South Korean schools.[20]

Japanese is written with a combination of kanji (Chinese characters adapted for Japanese) and kana (two writing systems representing the same sounds, composed primarily of syllables, each used for different purposes).[21][22] Unlike Korean hanja, however, kanji can be used to write both Sino-Japanese words and native Japanese words.

Historically, both Korean and Japanese were written solely with Chinese characters, with the writing experiencing a gradual mutation through centuries into its modern form.[23]

Both languages have similar elaborate, multilevel systems of honorifics, and furthermore both Korean and Japanese also separate the concept of honorifics from formality in speech and writing in their own ways (See Korean speech levels and Honorific speech in Japanese § Grammatical overview). They are cited as the two most elaborate honorific systems, perhaps unrivaled by any other languages.[24] It has been argued that certain honorific words may share a common origin.[25] Uniquely, the honorifics rely heavily on changing verb conjugations rather than only using t-v distinction or other common methods of signifying honorifics. See Korean honorifics and Japanese honorifics.

• Baekje language
• Classification of the Japonic languages
  • Classification of Japonic languages#Similarities between Japanese and Koreanic languages
• Japonic languages
• Koreanic languages
• Peninsular Japonic