(with) Pinch of salt

Its an English adaptation of a Latin phrase. This can be used as an idiom, which means - not taking anything literally, or taking anything with skepticism (doubtfully, questions in mind attitude). The phrase history suggests that if you take anything (especially poison) with pinch (or grain) of salt, the affect of poison will be less severe.

This phrase can be beautifully used in a sentence where we want to doubt the some (not whole) of some one's saying or story. It means, we can accept part but not whole of some one's version of story.

"Don't be disappointed, take John's comments with grain of salt"
"Her story of illness seems exaggerated, I always take them with a pinch of salt"

Further reading : http://www.phrases.org.uk/meanings/take-with-a-grain-of-salt.html