Do upper class french people speak with a different accent?
Some verrrrry snob people have posh accents, elongating their syllables mostly. Usually you have regional accents, but once you reach a certain level it is very hard to know which social class you come from as good French is accentless. As said above vocabulary is a better indication, as well as using the tenses right. Having a wider vocabulary and using complex past tenses for example is enough to have you pegged as upper middle class and higher. This, by the way, is a wide generality, I have known upper class people who can’t conjugate and shop owners who could put a litterature teacher to shame.