It's very hard to live in Paris if you are not fluent in French... Or you're doomed to live amongst ex-pats, which defeats the purpose of the experience.
Although Paris is the most visited city in the world. It also has a reputation amongst the global cities as being unfriendly. Enough that the Paris Tourist Board and Chamber of Commerce have launched a campaign to educate service workers on treating tourists better. Tourists also do not spend as much money in Paris. It is number 3 in that regard. This is likely due to Paris' centralized position. It may more likely be a stop-through on the way to a visitors' final destination.
You can be perfectly fine on English in almost any large city in the world, but there is more of a friction in Paris when interacting in English than in many other European capitals.
I know the reputation, but the times I've visited Paris everyone has been extremely helpful and polite. What I do see, occasionally, is American and German tourists who ignore local customs, behave rudely, and then get offended when the Parisians respond rudely to their own boorishness.
The only really bad experience I've ever had in Paris was with an eastern european cab driver who droned truly horrendous racist screeds about black African prostitutes ruining Paris my entire ride.
