Why does Japanese use kanji when it has kana?

[ilmari]

I would also add a phonetic reason. Japanese has a very limited sound system (5 vowels and limited C+V combinations, no tones, etc.), which makes it highly impractical to write only in kana - you wil end up with too many homophones, especially for Sino-Japanese words. This is different from what we have in Korean, for instance, where the sound system is much more complex than Japanese - which allows to write today almost only in hangul, with very few hanja being used.

Having said that, different historical circumstances may have lead to Japanese writing only in kana, or even in latin letters.

[Deinonysus]

As mentioned earlier, there are some benefits to logographic writing systems that make up for the extra time investment. It is easier to recognize a unique symbol than to recognize a group of phonetic symbols. In fact, when I was recently learning some Sumerian Cuneiform symbols, I would often recognize the symbol in my Anki deck before I could read the romanization—and of course I have been using the Roman alphabet all my life. In addition, a writing system can be a strong cultural symbol and a point of pride.

The fact of the matter is, I can think of a few cases where a logographic writing system has been replaced by a sound-based writing system (alphabet, syllabary, etc), and in none of those cases did they simply decide that the sound-based system was easier:

• The Akkadians coexisted with Canaanites (who invented the first alphabet) and Arameans (who adapted the alphabet for their own use) for about a millennium after alphabets became widely used, but despite this they never abandoned their cuneiform writing system, which used a combination of a syllabary and logograms. They only switched to the Aramaic alphabet when their own language died out and was supplanted by Aramaic, and even then they used cuneiform to write Akkadian as a liturgical language.
• The Egyptians only switched to the Coptic alphabet after centuries of Hellenic rule and cultural influence.
• The Mayans did not willingly switch to the Latin alphabet. Christian missionaries converted them by force and burned almost all of their books in the indigenous writing system. Only four books survived the purge, so most of our knowledge of their writing system comes from carvings, which were apparently too difficult to systematically destroy.

[verdastelo]

Excellent answer, Deinonysus!

I will add two more instances:

1. The Vietnamese switched from chữ nôm to chữ quốc ngữ during the French colonization. I doubt they would have abandoned the characters if they had remained independent.
2. The only instance (in my memory) where a culture consciously abandoned logographic writing for an alphabetic system is Korean. In the North, it was the party diktat and in the South, it was a struggle between traditionalists and Hangul-exclusivists, something akin to the arguments between славянофильство (Slavophiles) and западничество (Westernizers?) during Dostoevsky's time. In both Koreas, Hangul-exclusivity has won out. Here is a series of essays on the script change in Korea: On Hangul Supremacy & Exclusivity (한글전용-국한문혼용에 대하여), unfortunately accessible only from Archive.org. I love them.

[vonPeterhof]

[list=1]
[*] The Vietnamese switched from chữ nôm to chữ quốc ngữ during the French colonization. I doubt they would have abandoned the characters if they had remained independent.

Interesting that some articles on English Wikipedia related to the Vietnamese switch mention the example of Japan as an implicit argument in favor of scrapping Chinese characters in Vietnam. More specifically, the Japanese introduction of a universal public education system is compared favorably to Vietnam's retention of a Confucian education system, which in Vietnam was centered on learning Chinese classics. I suspect that the introduction of public education not necessarily implying the abolition of Chinese characters in Japan has to do with the previous existence of Buddhist-run popular educational establishments outside the Neo-Confucian system that had already resulted in relatively high kanji literacy rates.

[bolaobo]

I would also add a phonetic reason. Japanese has a very limited sound system (5 vowels and limited C+V combinations, no tones, etc.), which makes it highly impractical to write only in kana - you wil end up with too many homophones, especially for Sino-Japanese words. This is different from what we have in Korean, for instance, where the sound system is much more complex than Japanese - which allows to write today almost only in hangul, with very few hanja being used.

Having said that, different historical circumstances may have lead to Japanese writing only in kana, or even in latin letters.

Despite the more advanced sound system, Korean STILL has a lot of homonyms. I know learners who have reached a high-level in the language, and they say that knowing Hanja helps them learn high-level/technical vocabulary because it exposes the roots of the word and makes compounds easier to memorize. Maybe native Koreans don't need it, but the additional information comes in handy for learners who aren't as good at guessing from context.

[devilyoudont]

Adding a wrinkle here, but all of the pre-modern systems had syllabaries and abjads in place for use alongside the logograms... These systems were stable and lasted 1000+ years each, but none were as logogram-heavy as Japanese (besides Chinese of course). Just looking at languages using cuneiform you might have 1 language using 600ish logograms (Sumerian) and another with literally 8 (Persian). The cuneiform syllabary did not fully capture the sounds of all or even most of the languages which it was used for which also created problems around homonyms as well... For ancient people the solution was more or less to write an unpronounced logogram which narrowed the possible meanings of the word it clarified. These classifiers were used in all languages which used cuneiform, even those which practically used no other logograms. In Japanese-without-kanji, this system would look something like this:

人きしゃ　vs　車きしゃ
kisha vs kisha
(person)reporter vs (vehicle)train

Of course this is exactly how phono-semantic compounds function (90%+ of chinese characters) except Chinese innovated a way to do this within a single character rather than as a silent affix.

I think there is a mistaken tendency for us who use alphabetic systems to view alphabets as the result of some kind of evolutionary process. The earliest phase of our letters were Egyptian Hieroglyphs, so the alphabet is in some way a higher form. But the reality here is that every one who has ever written anything was an anatomically modern human. Language is inherently unstable, and writing is an imperfect tool to capture it. Situations might change and more languages could drift towards logographic systems again. Hittite only inherited at most 200 logograms from Akkadian, but it effectively created new logograms out of phonetically spelled Sumerian and Akkadian words--as if we took the latin word "aqua" and 100% of the time used this to write the word "water" but still pronounced the word "water" when we read "aqua" aloud. So, as Hittite once gained more logograms, as Japanese tends to use them more frequently today than at other points in the past, other languages could find uses for these systems again. Perhaps, increasingly novel and abstract uses of emoji, perhaps thru the rebus principle? Who knows!

[FyrsteSumarenINoreg]

Ainu language can do just fine with Katakana, why Japanese language could not?

[devilyoudont]

I can't comment too much on Ainu, but I am aware it uses a mixed script. Below is a sample copied from the website of the アイヌタイムズ... from this sample we can infer 1) Ainu uses less kanji than Japanese 2) Ainu uses kanji for proper nouns 3) Ainu uses kanji for loans from Japanese. For whatever reason, the modified kana which Ainu use display as standard after I copy and paste. I don't know how to reproduce them on my IME.

　タン　アイヌタイムズ　ケシト　ケシト　ア・サプテ　新聞　カ　ソモ　ネ　クス、カニ　アナク　タネ　ホシキ　アン　トゥミ　マカナク　アン　ヤ　カ　ケランペウテク。日本チーム　シネ　チーム　ネ　ヤッカ　コエイカウン　ワ　アン　ヤク　ピリカ　クニ　ク・ラム。

While trying to find an example online, I found it easier to find Ainu text using latin letters. アイヌタイムズ presents articles using both orthographies so here is the same text in latin letters:

tan Aynu-taimuzu kesto kesto a=sapte sinbun ka somo ne kusu, kani anak tane hoski an tumi makanak an ya ka k=erampewtek. Nippon-timu sine timu ne yakka koeykaun wa an yak pirka kuni ku=ramu.

[AllSubNoDub]

With Kanji:
why does japanese use kanji when it has kana? we can obviously write all 2136 jouyou meanings without them. Easy as 1+1=2, etc.

Kana only:
whydoesjapaneseusekanjiwhenithaskana? wecanobviouslywritealltwentyonehundredandthirtysixjouyoumeaningswithoutthem. easyasoneplusoneequalstwoetcetera.


Edited for correct number of jouyou kanji.

[ilmari]

There is a whole kana literature in the Heian period (794-1185). This is mainly women writings, like the famous Tale of Genji, but also poetry collections such as the Kokinshū. https://www.britannica.com/art/Japanese-literature/Classical-literature-Heian-period-794-1185

As far as I understand, these Heian works use few sino-japanese words - but please correct me if I'm wrong.