1. incredible 难以置信的，主语常常是表物的。
爱因斯坦的相对论在他第一次提出的时候似乎是难以置信的。(Einstein’s theory of relativity seemed incredible (unbelievable) at the time that he first introduced it.)
那位科学家以令人难以置信的热情投身于他的研究工作。(The scientist was devoted to his research work with incredible enthusiasm.)
真让人难以置信，她已经在那里待了一个星期了。(It seemed incredible that she had been there a week already.)
在现实生活中，环境有时确实会带来巧合，这些巧合除了19世纪的小说家之外，任何人都会觉得难以置信。(Yet, in real life, circumstances do sometimes conspire to bring about coincidences which anyone but a nineteenth century novelist would find incredible. (新概念3 L36))
在战时人们仍然想踢足球，这似乎不可思议。(It seemed incredible that people would still want to play football during a war)
你想象不到弗朗西丝卡多么希望得到父亲的同意。(It's incredible how much Francesca wants her father's approval)
很难相信他现在身无分文。(It's quite incredible to think that he now hasn't got a bean)
彼得行事如此麻木不仁，真是难以置信。(It's incredible that Peter can behave with such stupid lack of feeling.)
12岁的孩子能踩到踏板已经是不可思议，就更不用说开车了。(It is incredible that the 12-year-old managed to even reach the pedals, let alone drive the car.)
他用自己不可思议的幽默感逗我开心。(He used his incredible sense of humour to lift my spirits)
我们不应把孩子们告诉我们的一些不可思议的故事当成谎话而不予理睬。(We should not dismiss as lies the incredible stories that children may tell us.)
她过去的生活极其放纵。(She lived a wild and incredible life)
他活下来的概率非常小。(The odds against him surviving are incredible.)
我们从欧洲大陆进口数量惊人的奶酪。(We import an incredible amount of cheese from the Continent)
这是个不可思议的方法。(It's an incredible method.)
2. incredulous 不轻信的（主语常常是表人的）：
我不轻信报纸对这一事故的报导。(I’m incredulous about the newspaper report on this accident.)
我们不轻易相信有鬼。(We are incredulous about ghosts.)
“他强迫你做的？”她的语气里带着怀疑。(‘He made you do it?’ Her voice was incredulous.)
“你留下她不管了？”他的声音里含有不肯相信的味道。(“You left her all alone?” He sounded incredulous.)