While doing today's 《每日一句汉译英>>, I was pondering whether to use "incredible" or "incredulous", two words I have been having hard time to distinguish, then I googled...

============================================================

Incredible vs. incredulous

By Grammarist On February 7, 2011 · Add Comment · In Usage

Something that is difficult to believe is incredible. If you have trouble believing something, you are incredulous. The adjectives were once variants of each other, but they diverged a few centuries ago, and now they are no longer interchangeable. 

Examples

These writers use incredible and incredulous correctly:

What we’re seeing is quite incredible because this is the oldest society in the Arab world … [CNN]

David Nabity, one of the leading proponents of the recall, was incredulous that the measure had apparently failed. [New York Times]

… their campaigns are probably over, for all intents, barring an incredible comeback. [Los Angeles Times]

Neighbors were incredulous Bilotto would have a firearm with four kids, let alone an illegal one. [Gothamist]

Although the distinction between incredible and incredulous has been deeply engrained for some time, some writers still use incredulous when they mean incredible—for example:

Last October, after reading what I thought was an incredulous weight loss book, I threw out a challenge to my column readers . . . [Denver Post]

The storyline may sound incredulous but what is more so is that not a single feminist or woman’s aid organisation has balked over it. [New Straits Times]