72791
I grabbed this sentence off NHK news easy,
<https://www3.nhk.or.jp/news/easy/k10012139481000/k10012139481000.html> .

The sentence is,
国立成育医療研究センターと国立がん研究センターは、２０１６年と２０１７年,約８００の病院などでがんだとわかった若い世代について調べました。

The following sentence uses がんだとわかった as well. I believe this to be がん as in
cancer, followed by the copula then the quotation particle and 分かる. I'm having
some confusion as to what the subject is though. First off, I think there are
two subjects. The first being the two research centers marked by は. They are
doing the investigating (調べました).

２０１６年と２０１７年,約８００の病院などで is marking the time and place. 2016/2017, at
approximately 800 hospitals.

Then, for the modifier of 世代, "がんだとわかった若い世代, I'd get something like "It is
understood to be cancer young generation" or more fitted for English 'the
young generation who are known to have cancer." The だ is for cancer as a state
of being so there should be something like Zeroががんだとわかった. What's the zero or
unsaid subject here though? 人たち? It?

I'm mainly confused at why the だ is used with an unsaid subject. I know it
happens all the time but especially since this clause is modifiying 若い世代, it
seems a bit redunant to me. If you take the だ off, then there is no state of
being inferred for the young generation with cancer. It happens in the
following sentence too and is modifying 人. がんだとわかった５万７７８８人.

Sorry for the rambling but if anyone can help me understand this it would be
much appreciated. Thanks
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2019-10-27T22:36:22.850
72787
2019-10-28T04:30:18.737
33404
question
copula
How does がんだとわかった work in this sentence?
> I'm having some confusion as to what the subject is though.

This 癌だと分かった forms a (part of a) relative clause that modifies 若い世代, so the
subject is 若い世代. You can think of a "base" sentence like 彼らは癌だと分かった, but read
this like "It turned out that they had cancers" rather than "They understood
they had cancers". Note that Japanese diseases name [work as a noun and no-
adjective](https://japanese.stackexchange.com/a/16303/5010).

The basic structure of this sentence is:

> 国立成育医療研究センターと国立がん研究センターは、Xについて調べました。  
>  NCCHD and NCC investigated X.

Where this `X` is a long noun phrase including a long relative clause:

> （2016年と2017年、約800の病院などでがんだとわかった→）若い世代  
>  people of younger generations who were diagnosed as having a cancer at 800
> medical institutes in 2016 and 2017
CC BY-SA 4.0
2019-10-28T04:30:18.737
72791
2019-10-28T04:30:18.737
5010
72787
answer