I was taught that cutting pieces, putting down your knife and eating only with your fork is boorish and that only old rural people (and Americans) eat that way.
This is the first thing that popped into my head when I read the OP.
My parents immigrated to Canada from the Netherlands in 1964, when they were in their late '30s. My mother loved Canada and picked up a lot of North American mannerisms, but what drove her up the wall was seeing her friends cutting their food with their right hands, putingt their knives down, and picking up their forks with their right hands. My mother always said her own mother would have smacked her senseless if she'd dared to eat like that.
Needless to say I grew up eating the European way, with the fork in the left hand and the knife in my right. I'm left-handed, but never had issues cutting my food with my right hand. When I'm doing food preparation and using sharp knives I use my left hand, though, and I always use my left hand for spoons. I was also taught not to scoop up food with my fork, but to move food onto the fork with the knife. Because of this I eat with a fork and knife whether or not I need to cut my food.