Actually, the F-word comes from the German "ficken", meaning " to strike". I've read about this etymology of the word elsewhere (it might be in "The Book of Misinformation", but I'm not sure.

The discussion of common-law marriages reminds me of a divorce case with which I am familiar (no, it wasn't mine) from the early 80s. The wife goes in to see a lawyer, seeking a divorce; and in due course the lawyer asks when she and her husband were married. She replied something like "oh, we never had a formal wedding. We lived together for a while; and then my husband pointed out that we were married under common law." The woman was shocked to realize that she lived in a state which no longer recognizes common law; and even more shocked to realize that she did not have the rights which a state-recognized marriage gives to a couple. Eventually she got child support for her son; but alimony was out of the question, even though her fake-husband was making good money in construction work.