Japanese and Korean language: a first-pass comparison

Since I started learning Korean through KoreanClass101, I was surprisd almost immediately by how similar Japanese and Korean languages are. It’s something you might read about, but when you are familiar with one language, the other seems surprisingly easy in some ways. You still have to invest a lot of time and practice, but learning Korean is easier than I thought because I feel like I’ve done some of the hard work already.

By the time I started Beginner Lesson 2, I already noticed that there were strong similarities. The two languages are technically not related at all, but instead have influenced each other because they exist side-by-side. Linguists call this a sprachbund effect.

For practical purposes though, learning one definitely seems to make it easier to learn the other, based on my very, very limited experience so far. I studied Japanese for years, and speak it periodically with my wife and daughter at home, so when I started learning Korean, I was surprised to find a lot of similarities. In the past, I’ve studied Mandarin Chinese, Vietnamese (2 years in college + Vietnam) and Thai, plus Latin and German when I was younger,1 but the similarities described below are only found in Korean and Japanese as far as I know.


Both languages heavily use the same types of particles (not found in other languages I am aware of):

Topic Particle Identifyinga Particle Location or Target Particle Object Particle Possessive Particle
Japanese は wab が ga に ni を wo の no
Korean 는/은 neun/eun 이/가 i/ga 에 e 를/을 reul/eul 의 aec

Note: In Korean, some particles will change a little depending on whether the letter before it is a vowel or consonant. This helps the sound become smoother. The i/ga particle is the most noticeable and still confuses me when I hear it.

a Usually this is called the “subject particle” but Tae Kim makes a good case for why this should be called the identifier particle.

b Normally this is the letter “ha”, but is pronounced “wa” in the context of a particle.

c Normally this is pronounced as “ui” (say “oo” while grinning), but is pronounced “ae” in the context of a particle.

So, the sentence “I have a girlfriend” in both languages has a similar structure (particles and verb highlighted):

  • 彼女います
  • 여자친구있어요.


As both Korean and Japanese culture are influenced by Confucianism, they both place heavy emphasis on respect for one’s elders (even if they’re only a couple years older), and on protocol. So both languages have different levels of politeness.

Both languages can broadly be said to have three levels of politeness:

  • “Formal polite” speech, as KoreanClass101 calls it, used in formal occasions (e.g. business, talking to elderly, talking with heads of state, etc). This is roughly analogous to Keigo in Japanese in that it’s pretty formal and polite too. From what I can tell so far though, they’re not quite the same, but do reflect very formal, polite speech and is frequently used with one’s boss or teacher.
  • “Normal polite” speech, again as coined by KoreanClass101. This is polite speech you might use around people when exchanging small talk like your neighbors, someone you’re friendly with but not close “buddies” with. In a way, it’s the most “neutral” form to use.
  • “Informal” speech which is used with close family members and good friends. Using polite speech with good friends and family would sound strange of course. :)

This is somewhat related to the “social concentric circles” related to social “in-groups” and “out-groups”.

Chinese Loan Words

Again, both languages inherited quite a bit from China, and thus there are a lot of imported Chinese words. Unlike the native Korean or Japanese words, which sounds very different from one another, the Chinese loan words are recognizable in both languages. Many of these words can also become verbs by adding at the end する (suru) in Japanese or 하다 (hada) in Korean.

To complicate matters though, Meiji Period Japan also coined a lot of new phrases using old Chinese words in new, modern contexts (e.g. political terms, scientific terms, etc). These words, in turned, became part of Korean language due to its annexation by Japan. So, while there are many Chinese loan-words in both languages, not all of the words are necessarily of Chinese origin.

Some examples:

  • 約束 (yakusoku) and 약속 (yaksok), which both mean “promise”.
  • 木星 (mokusei) and 목성 (mokseong), which both mean “Jupiter”.
  • 時代 (jidai) and 시대 (shidae), which both mean “generation, period of time”.

Both languages also have “native” ways of counting and Sinified (Chinese) ways of counting. In some cases you use the native counting method, and in some circumstances you use the Chinese-style numbers.

When I studied Vietnamese in college, there were also many Chinese-imported words similar to above, as well as two different counting systems. Clearly China dominated East Asian culture, the same way Greco-Roman culture dominated the West.

But in spite of the similarities, there are notable differences between the two languages, making both a challenge.

Writing System

Japanese and Korean writing systems are pretty different. Japanese has two different syllabary (Hiragana and Katakana), plus Chinese characters (Kanji) mixed in to help identify nouns, verbs, etc. Even if you learn the kana, you still have to invest a lot of time learning Kanji as well. It’s quite complicated and time-consuming

Korean on the other hand uses only one system: Hangeul. Hangeul is more complicated up-front than Hiragana and Katakana, plus there are more sound changes, shifts, etc. So, you have to invest more time learning hangeul than you would Kana. Despite this, I still make frequent typos. On the other hand, Chinese characters (hanja) are used quite infrequently, and most Koreans know 50-300 only, so once you master Hangeul, that’s all you have to do.


Japanese pronunciation is noticeably simpler than Korean. It has a very limited number of sounds, and there are few sound shifts, so foreigners can learn to pronounce Japanese fairly quick (not perfect, but good enough). On the other hand, Japanese has a lot of difficulty pronouncing foreign words because it has fewer sounds.

Korean language has a more complex phonology (set of sounds), this helps it to approximate foreign words more smoothly, but also means that foreigners have a harder time learning to pronounce Korean correctly. Plus, to confuse things, written Korean and spoken Korean are not always pronounced the same (as a friend warned me).

While you have to spend more time learning to read Japanese, you have to spend more time practicing listening and pronunciation of Korean.


Some basic, fundamental verbs in Japanese and Korean are different than one another. For example Japanese has two verbs to describe existence: ある (aru) for inanimate objects and いる (iru) for living objects (e.g. People, animals). However in Korean there is only one verb, 있다 (itda). On the other hand, Korean has a separate verb for non-existence, 없다 (eoptda), while Japanese only conjugates the verbs above in the negative. Also Korean has verbs for “to be” and “not to be”, 이다 (Ida) and 아니다 (anida) respectively while Japanese uses a declarative particle, だ instead.


From my initial experiences, there are many things that Japanese and Korean have in common, but also key differences that make studying both fun and challenging. I hope to write more as time goes on. :-)

P.S. Finally back on schedule after two weeks of non-standard posts, misfires, and so on. :p

1 Based on my limited experience, every language you study makes it easier to learn additional languages. Why? Because even if the languages are totally different, the same concepts, pronunciations and such will often reappear. I had given serious thought to getting a degree in Linguistics when I was in college, but I chose a slightly different degree. Maybe I should go back though and get a Masters degree someday though when life slows down. :)

About Doug

A fellow who dwells upon the Pale Blue Dot who spends his days obsessing over things like Buddhism, KPop music, foreign languages, BSD UNIX and science fiction.

10 thoughts on “Japanese and Korean language: a first-pass comparison

  1. You have studied a lot. How do you find the motivation, and the time to study so much? Are you a student?

  2. Hi Pooh,

    I think it’s just a case of doing something you like a lot. Coincidentally, I have a post about that on Wednesday. Stay tuned. :)

  3. Another excellent posting. It will come as no surprise to you that I enjoyed reading this. From what I understand, Japanese and Korean have generally been treated as “isolates,” but some linguistics are entertaining the idea they might be related in some way. Interesting that they would have such structural (grammatical) similarities despite phonological (sound) differences. Re: Sinitic (Chinese) loanwords – it often surprises me when I find out how certain “Chinese” words are pronounced in modern Japanese and Korean. To my ear, many of these pronunciations sound much “closer” to modern southern varieties of speech (e.g. Southern Min/Taiwanese) than Mandarin. Probably has something to do with when these words were borrowed, and how Mandarin has transformed/diverged since then.

  4. *linguists, not linguistics (above).

    P.S. I wonder if the Sinitic borrowings in Korean came through Japanese or if this happened “in parallel fashion,” as it were? Funny to think about the possibility of a trans-linguistic game of telephone: sounds morphing from one language to (through) another.

  5. Hi Jonathan,

    Yeah, I think it will take a lot more research to answer the question of whether Korean and Japanese are actually related or not. On an old post about Prince Shotoku, I mentioned about the large influx of immigrants from the Korean peninsula in the earliest periods of history. My guess (an amateur guess) is that during this time they influenced Japanese grammar so that it loosk more like Korean grammar. The “native” (non-Chinese words) sound completely different than each other, but the grammar is so similar. I guess it’s like the Norman invasion of England, which rapidly changed English grammar and vocab, whcih you are no doubt familiar with. :)

    As for the pronunciation, you’re right! There’s a lot of evidence that the words were borrowed more from Fujian or other such areas (maybe because they were popular ports):


  6. Hello hoihoi and welcome! You’re right about wasei kango, thanks for the reminder. Many wasei-kango words were made during the Meiji Period and became part of other languages as Asia wanted to modernize.

    I did delete the subsequent posts though as they were becoming off-topic but they were interesting to read, thank you.

  7. Very interesting indeed, thank you Doug and everyone commenting.
    I am just a bit perplexed about the percentage mentioned by hoihoi.The articles talks about “statistics, social sciences and humanities”, and of course it doesn’t give more information since that is not its purpose, but I would be curious to know where the figure comes out from.
    Plus it would be nice to note how much is the 70% of modern words in relation to the (rough) total number of words of contemporary Chinese.
    As it is, it sounds almost as if modern Chinese is made to a great extent by Japanese, which I doubt is the case, and although the article clearly mentions modern words, not all the words, the reader can easily misunderstand (as I did when reading without paying enough attention:)

  8. Hi Aldo, and welcome!

    Good questions raised about the article, by the way. As I understand it, Japan was the first Asian country to industrialize, so they had to coin a bunch of new terms using old Chinese characters.

    These words were later introduced by people in Korea, China and Vietnam radicals who tried to modernize their own countries in the face of Western pressure. When Japan conquered parts of Asia, such words were also introduced or reaffirmed.

    However, as you said, this only applies to mostly scientific/political words. The bulk of the languages derived their vocabulary from classical Chinese or just native words.

    Anyhow, that’s my understanding of it.

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