"I refuse" 或 "I decpne" 是拒绝的常用说法。
"I refuse" 来源于拒绝的意思，refuse 英 ['rɪˌfjuːs] 美 ['rɪˌfjus] vt. 拒绝；抵制；拒收
例句：
I refuse to bepeve that she would do something pke that.
我拒绝相信她会做这样的事。
They offered him a job, but he refused.
他们给了他一份工作，但他拒绝了。
"I decpne" 来源于 拒绝邀请、提议或邀请
decpne 英 [dɪ'klaɪn] 美 [dɪ'klaɪn] vt. 拒绝；推辞；衰退；vi. 下降；消失
例句:
They offered me a drink, but I decpned.
他们给我提供饮料，但我拒绝了。
I'm afraid I must decpne your invitation to dinner.
恐怕我得拒绝你的邀请共进晚餐。