I was well aware that Benjamin [...] is commonly used for the youngest sonUh, colour me stupid if you will (or sleep-deprived -- I've been up since three thirty this morning, after less than two hours of tossing and turning) but what do you mean by "is commonly used for the youngest son"?
That is, I'm not quite sure whether you meant that sons one is determined will remain one's last offspring are often given the name Benjamin... Or that one speaks of "our Benjamin", meaning "our youngest", even when the offspring in question isn't actually *named* Benjamin.
What I meant by "there is a *concept*" [quoting myself from memory] was the latter. Did you mean the former, or are you saying the latter exists "as a concept" in English too?
Blearily yours,