Gengulphus, how can I ever fail now (after your excellent explanation) to forget to begin sentences with "hélas" in order to signal my intention right at the outset? Nice linguistic device and I will try it out very soon, to gauge its effects!
Betty, and Norman, thanks for à la rigueur; I don't think that I always listen as carefully as I might.
Confronter is useful to know though I can't say that I have paid it much attention.
The one I really like is cohabitation in the political sense. For example, a right- and a left-wing politician working together to achieve results. I suppose that, in English, we do say, oh, don't they make very odd bedfellows?
It's one of the rare senses in which getting into bed with someone else doesn't necessarily lead to anything to do with sex?
N'allez pas trop vite - Proust