I've seen some words with とお and とう and I was wondering how are you supposed
to know which one, and if there is any difference in pronunciation.
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2018-05-02T03:29:30.660
58294
2018-05-02T08:10:30.017
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question
grammar pronunciation
What is the difference between う and お when they come after an -o sound? Ex. とお and とう
I guess you mean how to know which kana to use for a word that you've heard,
but don't know how to write?

I'm not a native speaker, but I think the pronunciation difference is quite
subtle. It might be difficult to know which one if you hear a word for the
first time. Comparing とお in 遠い to とう in 当然 for example, I don't think I'd be
able to guess if I heard them for the first time, and didn't know the kana
already.

That said, as a rule of thumb, I feel that とう is much more common, so if
you're not sure that's probably the safer guess. Other than that, depending on
your vocabulary, how well you know kanji pronunciations, and whether you know
or can guess the meaning of the word from context, you might be able to make a
guess at which (if any) kanji is used, and from there know which kana.
CC BY-SA 4.0
2018-05-02T08:10:30.017
58296
2018-05-02T08:10:30.017
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58294
answer