What language do the townsfolk of so-called 'Clervaux' speak? edit

I bet, notwithstanding this article willfully misleadingly choosing the (somehow of a place in Luxemburg) French(?) spelling: Clervaux, that most of it's townsfolk speak German and dialects thereof and not French/Walloon/Luxembourg-French or whatever. And, of the foregoing Romance tungs, hardly ever at home indoors.