理由を知りたい

want to know the reason

→ 理由

phrase Uncommon #12,147

want to know the reason Used to express a desire to know why something happened or the reason for something. 理由 means “reason,” 知り means “know,” and たい expresses want.

JA: 彼が急に帰った理由を知りたい。

EN: I want to know why he suddenly went home.

出してくれとは言わないからなぜ閉じ込められたのか教えてくれ理由を知りたいんだ

I’m not asking you to let me out, so just tell me why I was locked up. I want to know the reason.

— オールド・ボーイ (2003)

私はその理由を知りたい。

I want to know the reason.

傷の理由を知りたい？

Do you want to know how I got this scar?

— 落下の解剖学 (2023)

トムとメアリーが今日ここにいない理由を知りたい？

Do you want to know why Tom and Mary aren't here today?

トムがまだ結婚してない理由を知りたいんだ。

I want to know why Tom still hasn't gotten married.