「彼に結婚を真剣に考えているか聞きたいけど、反応が怖くて聞けない」
"I'm seriously thinking about marrying him and I want to ask him, but I can't ask because I'm afraid of his reaction."
I'm scared to ask how much it was because it looks super expensive.
この場合、次のような言い方ができますよ。
ーI'm scared to ask how much it was because it looks super expensive.
「すごく高価そうなので、いくらだったか怖くて聞けない」
I'm scared to ask ... で「怖くて聞けない」と言えます。
ご参考まで！
アメリカ合衆国 
カナダ 
