He's never lied to me before, so I have no reason to doubt his word. 以前他从未对我说过谎,因此我没有理由怀疑他说的话。
I don't doubt you - I'm not in any way questioning your assertion.
I have no reason to doubt her.
No one doubted his word.
A few months into the relationship something changed and I started to doubt him.
Do you doubt me?
See also: doubt verb