[后接宾语从句时,如主句为肯定句时用 if 或 whether 连接,如主句为否定句或疑问句时用 that 连接] 不信任,不相信,怀疑,疑惑:I never doubted you; I was sure you would bring me the money.
我从不怀疑你的,我肯定你会给我带来这笔钱的。
I doubt whether (或 if) he will want to participate.
我怀疑他是否愿意参加。
I don't doubt that she's telling the truth.
我并不怀疑她讲的是真话。
Do you doubt that I love you?
我爱你,对此你有怀疑吗?