Why can some words be written with or without okurigana? How do the uses differ?

Question

What is the difference for word compounds that can exist with 送り仮名 and without and still retain the same pronunciation?

As an example:

巻き貝　と　巻貝

取り引き　と　取引

If I'm correct, both of these are pronounced 「まきがい」 and 「とりひき」. Do they mean the same thing? If so, what would be a good reason for choosing one over the other. Also, how did it come about to be this way?

The only reason I could guess that both exist is because 「取り引き」 makes the reader pronounce it a specific way without leaving anything to question, but please correct me if this is incorrect.

Answer 1

Even though they are both used, there is an official one and those that are not.

When you consider the history of kanji incorporation into Japanese, first, there were Chinese writings. Then, people tried to read them as Japanese. Two techniques appeared: (i) kaeri-ten, which marks how the Chinese characters in the original Chinese writing are to be permuted when read so that the Chinese writing can be read as if it is Japanese, and (ii) okurigana, which marks the inflectional endings that vary in Japanese but not in Chinese.

Hence, the purpose of okurigana is to mark the varied part of a word. This works for verbs. Now, once a verb is turned into a noun, and starts to be recognized as a noun that is independent of the original verb, there is no more purpose to keep the okurigana. That is where the reduction of okurigana happens.

Variation among the okurigana reflects the fact that it is not clear when a deverbal noun is created: some people might feel a word is still an inflected form of a verb whereas other people may feel that the word has evolved into an independent noun and has lost connection to the original verb. There is an official web page 送り仮名の付け方, but people have varied perception.

Answer 2

I had the same question as you a long time ago, and at the time a translator friend gave me the following explanation.

With these kinds of compounds (I always forget if they're compound verbs or something else, so forgive me that I'm lacking terminology), writing with okurigana or not is equally fine. The reason the okurigana can be omitted is that those particular combinations of words have become so commonplace that the furigana is no longer always needed for people to know what they are.

You will see even more variance than what you have in your question. Attaching okurigana to only one word, for example 取引き, can also happen. And then when you throw in swapping hiragana for kanji, it gets even more varied.

Why would you choose one over the other? Knowing your audience and whether or not they can infer the right compound and reading without the furigana. Also for style. But make no mistake: the meaning and pronunciation are exactly the same.

Hope that helps.

Answer 3

When I was taught vocabulary, in some cases I was given words with okuriganas, in some cases without, and in exams, getting the okuriganas wrong would be blamed. Based on this education, my answer is: "Yes there is a difference: one of the two spellings is correct, and there is no rule telling you which one it is."