What is the difference between 〜となる and 〜になる?

Question

Is it a nuance difference? Is it formality?

EDIT

For example:

請求書のお支払いは現金のみとなりますので、ご了承くださいませ。

請求書のお支払いは現金のみになりますので、ご了承くださいませ。

I just made that example up, but for some reason, my gut tells me it's the first one, even though I don't see anything grammatically wrong with the second, either. Is it formality level only?

Answer 1

Pretty finely nuanced, I'd say. と is a quotative particle, but is also used to described the manner in which something is done, often figurative. ～となる can be used to mean "become like a ~" while ～になる is literally "become a ~".

Answer 2

I've asked this very question in the past and my research led me to the following definition which (surprisingly) differs from every other answer here so far:

～となる expresses a discrete change, while ～になる can express either a discrete or a continuous change.

You can feasibly use ～になる for everything, since it covers all cases, but in cases where you want to use the most suitable grammatical phrasing (such as in formal situations), you often see this distinction made.

Examples:

その島は去年、無人島となった。 (～となる because the change from "inhabited" to "uninhabited" is discrete and happens the instant the last person leaves.)

デビューした後、彼はだんだん人気者になっていった。 (～になる because popularity changes continuously in unmeasurable steps.)

スカイツリーは現在、日本一高い建造物となっている。 (～となる because the title of "tallest building in Japan" applies to exactly one building, and a building cannot gradually become the tallest. It either is or it isn't.)

季節はこれから夏になっていく。 (～になる because the change in seasons is a gradual, progressive one.)

電線事故のため、新山口駅は終点となります。 (～となる because the title of "terminal station" only belongs to one station, and a station can't hold it partially.)

Your example in the question illustrates a discrete change in state (or more precisely, a discrete difference between 現金 and all other forms of payment), so both ～となる and ～になる are acceptable. However, since ～となる is "built" for such situations as these, it sounds more "proper" to use ～となる.

I suspect this rule also applies to the ～とする and ～にする forms, but I would have to do more research to confirm this.

Answer 3

From what I have learned and observed, ～となる implies a "suppose if" conditional, something similar to "suppose if it is the case that [X] would become [Y] then" where as ～になる simply means "[X] becomes [Y]".

「請求書のお支払いは現金のみとなりますので、ご了承くださいませ。」 would mean something like "Suppose if you need to pay your purchase by cash, we hope to get your understanding.". This implies that there are times that the shop does allow you to pay using other means than cash.

「請求書のお支払いは現金のみになりますので、ご了承くださいませ。」 lacks the "suppose if" connotation so it simply means "As a matter of fact, you need to pay your purchase by cash, so we hope to get your understanding.".

Answer 4

～となる　is also limited to nouns, I believe. The way I've heard it most often used is when the thing it becomes kind of fulfills some purpose. Kind of hard to explain. Here's my best example:

• 私は先生になります　→　I will become a teacher.
• 寄付となる金を貯金します　→　I deposit all money that will be (used for) donated.

Answer 5

I've heard that ~となります is popular to use because "it sounds formal", but actually its usage is incorrect, since です should be used instead. I'd guess that the same thing happens with になります、which would be just another form of saying です incorrectly (in this context).

Formalish way : 請求書のお支払いは現金のみとなりますので、ご了承くださいませ。

Correct way : 請求書のお支払いは現金のみですので、ご了承くださいませ。

Link: http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1119559566

Answer 6

There's another distinction between になる and となる: when the resultant state of the change is irreversible or final, となる is preferable. See this related answer.

Answer 7

According to "A Dictionary of Intermediate Japanese", there are only 2 differences between になる and となる.

(1) となる is more formal and only used in written Japanese.

(2) となる cannot be used with な-adjectives.