TAKOBOTO

Vn, As well not to ~
as well not to buy them

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サッカーでにほんがかって、かんこくじんのきむさんがどんなきもちかなんて、そんなこと、いわずもがなのことだよ。

When Japan wins at football (soccer), you don't even need to ask to know how the Korean Mr. Kim feels.

あたらしいでんきせいひんなんて、かわずもがなで、かうとろくなものがない。

You might as well not buy those new electronic gadgets. If you do then nothing good will come of it.

あのひとのかくぶんしょうにはむくもがなといえることばがおおい。

In his writings, there are a number of words which might better have been left out.

Conists of verb in 未然形+ず, the classical verb of negation, and the sentence-final classical particle もがな.
もがな:願望を表す。〜といいなあ。

blutorange

Two general uses, 1. Something doesn't need doing / saying.

Amatuka

2. Something should not be done / said [although may be anyway to ones regret]

Amatuka

NOTE: This is /relatively/ low usage in modern Japanese - but appeared on 2000 JLPT level 1.

Amatuka

I agree with NOTE. I asked J co-workers if they use 買わずもがな, I was asked the meanings. I know only 言わずもがな.

Miki

Formed by V-nai base + ずもがな
e.g. 買う→買わない→買わずもがな

Vn = V-nai base

Amatuka

もがな dates bqck to the Heian era, and it means that what precedes もがな would be the desire of the speaker. It is an archaic Japanese which only finds its use in some set expressions, such as 言わずもがな,which literally would mean "I desire that I do not say that" that would include the case of my regret for having said what I said.
My 広辞苑 shows the following:
あらずもがな、言わずもがな、無くもがな、やらずもがな and 由もがな.
While 買わずもがな is grammatically correct, I am not sure if it is actually used.
In any event, except perhaps 言わずもがな, all other instances of the use of もがな are pretty archaic.

bamboo4

なくもがな 【無くもがな】

（連語）

ないほうがよい。あらずもがな。
「あの一言は≠ｾった」「≠ﾌ差しで口」

kanoko

Thanks for examples. I have been going through old JLPT and was stumped by this one.

higashinoK:go