Do they still speak French in France, or has that been outlawed already?
I don't know. You can stay conscious and aware that you've been beheaded for up to 20 seconds or so after a quick, clean decapitation. That would be a horrifying 20 seconds.
I googled it a while ago when ISIS was beading everybody. That's what I found out from sketchy anecdotal evidence. However, pretty hard to confirm in all cases, I imagine.