を疑う

suspect; doubt

→ を
phrase Uncommon #9,057
suspect; doubt Used when suspecting a person of wrongdoing or doubting the truth of something, including one's own judgment or ability. The particle を marks the person or thing being suspected or doubted.
JA: 私は彼を疑う。
EN: I suspect him.

彼の誠実さを疑うのなら彼に援助を求める

If you doubt his integrity, don't ask him for help.

評判正直者を疑うのが俺達の商売

Our business is to suspect even those renowned for their honesty.

— サイコ (1960)

バカこれでもを疑う

Idiot. You still don't trust me?

— オールド・ボーイ (2003)

わたしはそれの真意を疑う

I doubt its true meaning.

私はその文書本物を疑う

I doubt whether that document is authentic.

を疑うのもいい加減にしろ

Enough with suspecting everyone.

— 自転車泥棒 (1948)