There is a common belief that a bitter rivalry exists between French people and Americans. Having spent a significant amount of time in France, I know this is vastly overblown—sure, there are a few folks here and there who don’t like each other—but generally speaking if either party approaches the other respectfully, they will be treated respectfully in turn.
In cases where this is true, however, it is highly likely that an American visitor approached the French person, in France, addressing them immediately in English. While this is acceptable (and in some cases even desirable) behavior in some parts of Europe, making no effort to learn even a few basic pleasantries is probably the average French person’s No. 1 beef against Americans.
It’s not hard to learn your pleases, thank yous, excuse mes and good mornings. So if you want to make your time in France more enjoyable, commit a few to memory, practice some pronunciation, and you’ll be pleasantly surprised how easily it is to interact with locals here. They may not like to admit it, but many French people speak at least basic English, which makes sense given the importance of tourism to the country’s economy and it’s close economic links to England. But you’ll probably never learn the extent of their English skills unless you can start your approach with a word in French.