out of the question
彼の理論を理解することは問題外だ。
Understanding his theory is out of the question.
彼の提案は問題外だ。
His proposal is out of the question.
そんな些細な事は問題外だ。
Such a trivial matter is out of the question.
それは問題外だよ。
That's out of the question.
彼の意見は問題外だ。
His opinion is out of the question.
彼は問題外だ。
He's out of the question.