I’ve been studying Japanese and I just started using Imabi to get a more thorough grasp on grammar but the adjectival noun has got me confused.
For example this sentence:
Why is データが安全でないことが原因であることがある。 correct
but not データが安全じゃないことが原因であることがある。edit:idek if it’s incorrect
Even though he uses a similar structure here, 当たり前が当たり前じゃなかったことに気づいた。 but in past tense. I’m not completely sure when である and な should be used.
2 comments
Are you sure データが安全じゃないことが原因であることがある is grammatically incorrect or is it one of those cases where it is technically correct, but doesn’t sound natural thus should not be used?
The only thing possibly incorrect about the second sentence is that it mixes registers. If a speaker uses である instead of だ・な・(nothing) in a situation, they probably also use でない or ではない instead of じゃない。
But I also want to say that であること isn’t necessarily である for the sake of である tone. 原因なこと isn’t really used as far as I know. (But 原因なわけ is.)
Please remember that Imabi isn’t written by a native speaker and isn’t an authoritative reference. It’s a collection of in-depth notes, similar to what I can say here as a learner with some experience. (Just in more depth, the author is very diligent.)