Should I use 言う or いう in "はどういう意味ですか"?


On page 33 of the Lonely planet phrasebook for Japanese, 5th edition (ISBN
978-1-74104-231-3), the phrase given is

> What does 'deguchi' mean?
>
> 「出口」はどういう意味ですか？

The pronunciation guide has

> de-gu-chi wa dō yū i-mi des ka

I thought the いう should be 言う, because neither
[jisho.org](http://jisho.org/word/%E8%A8%80%E3%81%86) nor the [English edition
of Wiktionary](https://en.wiktionary.org/wiki/%E8%A8%80%E3%81%86#Japanese)
mention that kana should be used.

However, when I searched for "はどう意味ですか" (without いう or 言う to bias the search),
I found most of the matches were for "いう".

Should I use "言う" or "いう"? Also, is use of "言う" or "いう" specific to this
phrase, or is it normally written that way?




This is really a matter of style rather than any concrete language rule, but
the prevalent style is that _generally_ kanji should be used for 'content'
words, and kana should be used for 'function' words (though some words, as
you've seen, are kana no matter what, even if kanji for them does exist).

So, in this case, is いう a function word or a content word? It's a function
word, right? It doesn't add any _meaning_ to the sentence; it just holds the
sentence together. So kana would be the better choice under the most common
style.

言う _can_ be a content word, of course - for example, when reporting what
someone else has said - and in that case it's better to use kanji. But in this
case it is not a content word.

