Well, the title might not be very descriptive. Suppose Bob and Bill both own a car. Should the car be referred to as Bob and Bill’s car or Bob’s and Bill’s car?
I think the thing to do would be to try as hard as you can to make it work with “their car”.
Failing that, I don’t know. Personally, I’d go for “Bob and Bill’s car”.
It’s the custom to attach the “-'s” for possession to the last element in a phrase, although if there’s a way you can rephrase the sentence to avoid the slightly awkward construction, it’s a good idea. Shakespeare makes reference to “sing[ing] the King of Spain’s beard” in one of his plays (granted this is a different sort of phrase than “Bob and Bill’s car”) and most people would understand this as the beard belonging to the King of Spain, not to a man who “reigns over Spain’s beard.” Likewise the example sentence would be understood to mean “the car belonging to Bob and Bill.”
AFAIK, “Bill and Bob’s car” is the accepted form. There is no real “official” grammatical justification, other than that “Bill and Bob” is a compound noun. So when you say “I gave the car to Bill and Bob,” it’s understood that they both received the car and now own it jointly.
[Bill and Bob] got the car.
It’s the car of [Bill and Bob]. (Not: It’s the car of Bill and of Bob.)
Also, “Bill’s and Bob’s car” just sounds awkward.
I simply must defend the honour of my ancestor and namesake by pointing out that it was Francis Drake who *singed * the King of Spain’s beard by means of a surprise attack on Cadiz. As for his vocal skills, I must plead ignorance.
Regarding ‘Peter’s and Harriet’s correspondence’ and the convoluted explanation/justification thereof, it’s simpler and much clearer to add one word and write ‘Peter’s correspondence, and Harriet’s correspondence’
Yes, but when he was in the process of doing it, what present participle did he use? (Avoiding a Whitmanesque “I sing the beard electric”! ;))
As for Peter and Harriet and their epistolary activities, I suspect that was just a bit of Wimsey thrown in. (As Scripture tells us, “Be doers of the word, and not Sayers only!”)
According to your own Merriam Webster, ‘singe’ is always rendered ‘singeing’ in the ‘-ing’ form:
And I think you owe the bard an apology too.