Questions about the construction A が B(B is a noun)+のだ/のである?


「……そんな危険な大学出身者どもを、ありがたく受け入れるのが塾講師業界 **ってんだから** 」

Hi. The speaker is a 塾講師 and he is talking with a stranger in a bar.

Hi. I have some problems with the bold part. I know it equals 業界というのだから. But
I’m not sure if the という is 伝聞 here.

  1. Grammatically speaking, can we insert a だ between 業界 and って? And can we say 業界なのだから here?
  2. If we can, are the three versions (業界だってんだから、業界なのだから、業界ってんだから) the same in meaning and nuance?

A previous related thread addressed the pattern というのだから, where という was
interpreted as “they say”. But as far as I know, there are many cases where
the という in というのだから is just for emphasis without having a concrete meaning.
[https://japanese.stackexchange.com/questions/11046/what-are-the-usages-of-
のだから](https://japanese.stackexchange.com/questions/11046/what-are-the-usages-
of-%E3%81%AE%E3%81%A0%E3%81%8B%E3%82%89)

I ask this question because the topic sentence reminds me of another sentence
that I have come across before. Here goes it,

だがそれも無理からぬことなのかもしれない。 ただでさえ、女子の手作りクッキーをいただくなんてのは、他の男子たちの嫉妬の的だ。
しかもそれが、転入直後から、彼女にしたい女子ランキングを駆け上がった(と噂の)あの夜刀神十香のもの **だというのである。**

The context is that the girl 十香 made some cookies for the protagonist, of whom
the other boys were envious.

I was told the という in the bold part above meant “they say” but now that I read
it again, I think the という could also just be an emphasis without any meaning.
And unlike the first example, there is a だ between もの and という.

So let me summarize my question.

If the construction is A が B(B is a noun)+のだ/のである, as in the two sample
sentences, when is a だ immediately after B necessary and when is the だ
optional?

When is a って/という immediately before のだ/のである necessary? If the って/という is
unnecessary, なのだ works as well in the construction, I think.

Thank you.




The most complete form is 塾講師業界だというのだから, which can be contracted to
塾講師業界だってんだから, which in turn can be further contracted to 塾講師業界ってんだから.

The result of “reverse transformation” from the last one, 塾講師業界というのだから, is
also good, although I personally feel something is missing in it. (This is
precisely the reason I see 塾講師業界ってんだから more as a second-level contraction of
塾講師業界だというのだから than as a first-level contraction of 塾講師業界というのだから, at least in
this context.)

という in 塾講師業界だというのだから carries a sense of unexpectedness or surprise, as
suggested in [one](https://japanese.stackexchange.com/a/14400/43676) of the
answers to the earlier question. It’s like saying “the industry that willingly
accepts such rogue graduates is, of all industries, the cram school industry.”

I think the reason 塾講師業界 **だ** というのだから sounds more natural (at least to me)
than 塾講師業界というのだから is that the final だ or である is essential in stating the fact
whose unexpectedness is to be emphasized: そんな危険な大学出身者どもを、ありがたく受け入れるのが塾講師業界
**だ**.

Given enough context, 塾講師業界なのだから could also be interpreted the same way, but
it’s quite ambiguous as it can be easily interpreted as saying “since it’s the
cram school industry that …,” which sounds neutral and lacks emphasis.

という in あの夜刀神十香のものだというのである can also be understood the same way. The character
received the cookies from, of all girls in the school, _that_ Yatogami Toka.

あの夜刀神十香のものというのである, without だ, sounds even less natural than 塾講師業界というのだから. I
think this is because 「〜が塾講師業界」 could still be interpreted as something people
are saying, permitting という to immediately follow it, whereas this possibility
is ruled out with あの夜刀神十香のもの, which is a known fact for the narrator, not
hearsay.

Still, the contracted あの夜刀神十香のものってんだ sounds acceptable in casual speech. I
would suppose the speaker to be an 江戸っ子, though.

