Many people traveling in France would share the frustrating experience that they are ignored speaking English. Although English has borrowed and adopted French words, the French language has not welcomed the invasion of English words. They have been more resistant than most. The French have had a low against the encroachment of foreign words since as early as 1911, but this was considerably bolstered by the setting up in 1975 the Maintenance of the Purity of the French Language law, which introduced fines for using illegal anglicisms. You may safely conclude that the French take their language very seriously indeed.
No you won’t be fined for speaking English, but you won’t go very far either. In some of the old Paris dining establishments, especially the ones removed from the tourists’ tread, a hamburger is a steak haché (not le burger). A steak haché is made from minced beef, which is formed into patties ready for cooking and originates from France. Filet mignon generally refers to pork rather than beef. Some menus might provide a one-line English descriptions but don’t expect it to be the convention.
Estimates of the number of anglicisms in French have been estimated to be 2-3 percent or less. So it is altogether possible that the French are making a great deal out of very little. I suppose what really ranckles the French is not that they are borrowing so many words from the rest of the world but that the rest of the world is no longer borrowing so many from them. From the outset the government conceded defeat on a number of words that were too well established to drive out: gadget, holdup, weekend, blue jeans, self-service, and many others. They do recognize the global importance of English but prefer to speak French. But it’s a different case when it comes to relaxing at home in the evening.
But the English-speaking world can be better at looking after the borrowed words than the French were. Quite a number of words that English has absorbed no longer exist in France (at least not widely spoken). The French do not use nom de plume, double entendre, panache, bon viveur, or R.S.V.P. for répondez s’il vous plaît. Instead they write prière de répondre.