a question mark hang over something

US /ə ˈkwes.tʃən mɑːrk hæŋ ˈoʊ.vər ˈsʌm.θɪŋ/
UK /ə ˈkwes.tʃən mɑːrk hæŋ ˈoʊ.vər ˈsʌm.θɪŋ/
"a question mark hang over something" picture
1.

疑問符が残る, 不確実性がある

a feeling of doubt or uncertainty about something

:
A question mark hangs over the future of the company.
会社の将来には疑問符が残る
His involvement in the scandal still has a question mark hanging over it.
彼がスキャンダルに関与していることには、いまだに疑問符が残る