YOU SAID:

That is the single most stupid thing I've ever heard.

INTO JAPANESE

それは私が今までに聞いたことがある最も愚かなことです。

BACK INTO ENGLISH

That's the most foolish thing I've ever heard.

INTO JAPANESE

それは私が今まで聞いた中で最も愚かなことです。

BACK INTO ENGLISH

That is the most foolish thing I've ever heard.

INTO JAPANESE

それは私が今まで聞いた中で最も愚かなことです。

BACK INTO ENGLISH

That is the most foolish thing I've ever heard.