(2) It's like this:
The three translations that use this structure are as follows:
THE SECRET IS LIKE THIS
'that which is (the secret)' like this / this 'is' (declaration) ってのは
tte no waこういうこと
kō yū kotoさ
sa 1というのは
to yū no waこういうこと
kō yū kotoなんだよ
nan'da yo 1っていうのは
tte yū no waこれ
koreなんだ
nan'da 1Total 3There are minor variations:
というのは to yū no wa is the standard form. っていうのは ~tte yū no wa and ってのは ~tte no wa are both colloquial forms.
One uses これ kore 'this' instead of こういうこと kō yū koto 'a thing like this'.
One uses the jauntily assertive final particle さ sa, which attaches directly to the noun. The two others use なんだ nan'da, the shortened form of なのだ na no da. This is also used in making assertive statements. One reinforces this with the assertive particle よ yo.