-I could/couldn't care less: I feel this started out properly as "couldn't" and then people got lazy/used shortcuts in their speech. Very much like a "for all intentional purposes" type of phrase that has been incorrectly said -Entree: again just speculation... I think the US usage of this may have come from European multicourse meals... depending on the number of courses, you may start with hors d'oeuvres, soup, salad, etc... then move on to a First (Entree) and a Second as mains, before moving on to the wrap up with aperitifs, coffee, dessert, etc. As restaurants become more popular and accessible to the lower/working classes, courses were consolidated, and what was once called Entree/opener as a first main dish became the primary course of the meal.