Please indulge my quick question regarding grammar. Which snippet of dialogue is better when the narrator is on of a group of several people? a) "We were shaken to our core . . ." or b) "We were shaken to our cores . . . " In other words, was the single group shaken to its CORE, or were the multiple individuals shaken to their CORES? Intellectually, B seems more accurate, but somehow, it sounds wrong to me.