Many words in the English vocabulary are of French origin, most coming from the Anglo-Norman spoken by the upper classes in England for several hundred years after the Norman Conquest, before the language settled into what became Modern English.
They are most common in written English, where they retain French diacritics and are usually printed in italics.
In spoken English, at least some attempt is generally made to pronounce them as they would sound in French.
Also there are expressions that, even though grammatically correct, do not have the same meaning in French as the English words derived from them.
International authorities have adopted a number of words and phrases from French for use by speakers of all languages in voice communications during air-sea rescues.