I feel that there is a difference between "Jack and Jill's" and "Jack's and Jill's" and that depending on circumstances either could be correct. For example, as far as I am concerned, if Jack and Jill live in a house together then that is "Jack and Jill's house" whereas if Jack and Jill each have some (not necessarily shared) pencils then those are "Jack's and Jill's pencils" or alternately but much more awkwardly "Jack's pencils and Jill's pencils."
no subject
Date: 2009-06-19 04:21 pm (UTC)Jack's and Jill's or Jack and Jill's
And what is the possessive of an entity that has a possessive name already: McDonald's's?
no subject
Date: 2009-06-19 04:33 pm (UTC)I've seen "McDonald's'," but that makes me twitch. Almost all of the options make me twitch. I tend toward "belonging to McDonald's."
no subject
Date: 2009-06-19 04:44 pm (UTC)no subject
Date: 2009-06-19 10:55 pm (UTC)