France was much more linguistically diverse than England I think, especially by the late 18th century, most English people spoke English.

The statistics on French lnaguages are based on the study by Abbé Gregoire, which I always quote in essays yet I always lose after I've finished... I didn't think it was as high as 80% either. But there was an extraordinarly high number of people who couldn't even understand French.

One of the sad things about this revolution though is the way it treated minority languages... It's one of the reasons why Breton is so neglected now, and will soon be forgotten, is a remnant of this republique une et indivisible which recognises no language but French.