hard to believe, unbelievable
あなたの言うことは信じがたい。
What you're saying is hard to believe.
トムが心底ボストンに行きたいと思ってるとは、信じがたいな。
It's hard to believe that Tom really wants to go to Boston.
幼い頃の悲惨な日々は––信じがたい作り話のよう来たか
Did the miserable days of your childhood come back like an unbelievable made-up story?
— どん底作家の人生に幸あれ! (2019)
君の言うことは信じがたい。
What you’re saying is hard to believe.