う vs お ******

I stumbled a bit with the おう (king) Kanji and the 十日 (とおか) vocabulary because their long “o”’s are spelled differently in hiragana. One with an う and one with a お. Are there any rules or suggestions to help me remember which one to use? Or is it just a quirk I have to memorize for each individual word?


1 Like

It has to do with historical spellings so there isn’t really a rule. I’m pretty sure おう is more common overall.


Can you visualise TOO in the kanji for 十日?(the o’s become square)

I’ve not had the same issue with King, because I normally assume by default it will be おう unless I’ve memorised otherwise. However you could imagine a rude king who refers to his subjects as “O! you!”


Yes, long おs that come from Chinese are spelled おう and long おs that come from Japanese are spelled おお, so if you know whether it’s onyomi or kunyomi, you can keep it straight.


Aha! That’s what I needed to know! ありがとう!


:exploding_head: I can’t believe I’ve missed this for so long! Thanks for sharing your knowledge as always! <3


Jezus, someone give this man a cookie!

Leebo receives: 1x :cookie:

This is a good general rule, but like with any general rule, there are exceptions. One example off the top of my head (unless it’s secretly an on’yomi that I didn’t know about): 扇(おうぎ)= folding fan

My personal way of memorising it is by pronouncing each sort slightly differently: I pronounce おう as a long O, and おお as two separate O’s in rapid succession. They ultimately sound almost the same orally, but the difference stays pretty clear in my head. I mean, making the same sound twice requires a bit more effort, and it’s even a little stressful to do so rapidly, so the focus required helps the difference sink into my memory. I can’t find any good examples of words in which the second お of an おお combination takes the accent, but they almost certainly exist. (追おう is one such word, but it’s a bit of a cop-out because the おう was meant to be pronounced separately from the stem anyway…) With おう, however, the second kana can never take the accent unless it’s the beginning of another word.

I can’t say for sure whether Japanese people pronounce these two sounds differently (most probably don’t), I wouldn’t be surprised if they still maintain a sort of mental separation between the kana, since spelling a word out orally always involves saying it kana by kana, even if that spelling out is being done to teach somebody pronunciation. What I’m saying is that at least subconsciously, there’s probably an assumption that the individual kana sounds combined in quick succession generate the sounds we’re supposed to make, and so I make use of that in order to treat kana as a ‘phonetic’ system (i.e. I pronounce whatever I read as-is) while learning the right spelling at the same time.


Based on online JP dictionaries like this one: 扇(おうぎ)の意味 - goo国語辞書

It looks like おうぎ came from あおぐ, and perhaps due to a sound change it ended up becoming おうぎ, which could explain why the spelling doesn’t match the normal convention. Also while I relate to the two spellings having a different “feeling” to read, I’m pretty sure the linguistic consensus is that there is no phonetic difference between them in speech. They’re both pronounced the same, and the う sound that some people hear at the end (myself included) is I believe related to pitch drops in words where either the pitch drops on う or even from the natural steady drop in pitch over the course of speaking a sentence.

A lot of おお readings came from the second お once having a consonant but losing it over time. For example, it looks like狼(おおかみ, wolf)used to be pronounced おぽかみー>おふぉかみー>おをかみー>おおかみ
source : 狼 - Wiktionary).


Interesting. Still, I just wanted to point out that it’s only a general rule. Far more common words come to mind, like 今日(きょう)or おとうさん.

I think this is generally true, but I’ve never really looked into how Japanese people feel about it. Or perhaps what I’d be more interested to know is how Japanese people learn to pronounce these sounds. Are they explicitly taught as children that they’re the same? At the same time though, I honestly only do this ‘O-O’ thing for the long O sound, because (almost) none of the other long vowel sounds carries a similar risk of confusion.

I think this is true too, but that doesn’t mean there aren’t exceptions or cases of the two being interchangeable. What I mean by this is that the two sorts of pronunciation might both be acceptable, and it’s a matter of how much the speaker wants to separate the two sounds. For example, the instructor for the Japanese Pronunciation for Communication course on edX by Waseda University pronounces 一方 with quite a sharp drop in pitch in one of her lessons, saying ぽ and う (or お – it might have been an extended O sound, of course) almost as though they were two sounds. There are two ways to drop pitch, after all: smoothly or abruptly. She pronounced it with less emphasis in another lesson, and the second mora, whatever it was, definitely wasn’t as noticeable.

At the end of the day, perhaps I’m just a little too attached to my ‘trick’ to let go of it, but a big part of why I do it is because it works. I see so many people asking the very question that started this thread (this isn’t my first time responding to this issue), and I’m just glad I never need to ask it myself. Also, like I said, I’m pretty confident that what I do sounds the same, since I don’t allow myself any glottal stops between the two vowels.

Final justification: it’s kinda like what Japanese singers do when they pronounce 嗚呼(ああ)in the middle of a song – they use the same amount of force for the second vowel and change the pitch (e.g. あたしが隣にいる, the final line before the first chorus). Some words like 多い can be pronounced with the accent on the second syllable (LHL), and I think it’s pretty difficult/unnatural to attempt a smooth pitch transition, especially for such a short word where it’s pretty hard to do a ‘legato’ pitch variation. I’m trying to pronounce it both ways right now, and if I want something perfectly smooth, I need to slow down. Forcefully putting breath into the second syllable to get the right pitch is almost reflexive (I’m not talking about using a ‘stress accent’ here; it’s natural to inject a little more breath into your tone when increasing your pitch rapidly – almost all of us do it when singing) and tends to make it sound like a separate vowel even if I do my utmost to avoid any glottal stops. Both methods of pronunciation are practically equivalent as long as the pitch difference is large enough, and I think most Japanese pitch variations are about a third apart. That’s a fair jump if you’re speaking fast and need to raise the pitch of (i.e. accent) the second syllable, and difficult to do perfectly smoothly. That’s also probably why pitch drops tend to sound like separate vowels to many people: it’s hard to make them sound like exactly one smooth sound sliding down a third.

This topic was automatically closed 365 days after the last reply. New replies are no longer allowed.