The doorstep beverage sent by Marie was much appreciated.
I feel a little perkier now.
All the language chat has been fascinating. My father grew up speaking several languages and even as an adult, after decades away could make himself understood. This was very normal for his generation of his family - pretty much everyone spoke two languages (one with complete fluency, one to a good conversational standard), some of them spoke four or five to one level or another, and they picked up new ones very quickly.
I grew up hearing languages other than English, which at least meant that I knew about accent and emphasis without having to think about it, and I can recognise most of those languages if I ever see them written down. I surprise my DC by saying things like, 'No, he can't be X, he must be Y, just look at his name!' Amd they consult Wiki and find I'm right.
I have a smattering of various languages and find that I still remember phrases quite easily once I've heard them used. I suspect a lot of that is due to my exposure to varied languages as a child.
If I'd been properly fluent in a language of which I had a basic knowledge, I'd have brought my DC up to speak it. Not because it would have been wildly useful in itself, but for the mental flexibility that I think it would have given them.