質問: I was asked to nominalize `「傾聴」とは耳を傾けて熱心に聞く(--?--)。` These were the options: > > (1)「傾聴」とは耳を傾けて熱心に聞く`ということである`。 > > (2)「傾聴」とは耳を傾けて熱心に聞く`というのである`。 > > > With regard to grammar, I'd think that `というのである` can be substituted for `ということである` and be grammatically correct and have the same basic meaning. I feel that `というのである` is a superset of `ということである`. I found When choose の/こと or というの/ということ but the answer is not very good.
回答: They are not interchangeable. Only 「聞くということである」 is correct. Firstly, the という doesn't change anything important, so it ultimately comes down to the difference between the nominalizers こと and の. When the nominalizer immediately precedes the copula, only the nominalizer こと can be used to prevent confusion with the のだ/のである grammar. This rule applies even if the copula isn't explicitly said, as can be seen in the actual dictionary.goo.ne.jp definition of 傾聴.