"Grammar Girl" Mignon Fogarty gets to the bottom of this possible grammar gaffe. As a technical writer and editor, seeing the same mistakes over and over used to drive Mignon crazy. So she decided to enlighten others by sharing her "quick and dirty" language lessons online as Grammar Girl.
Despite Krista's insistence, Mignon says the possessive originally used in Oprah and Gayle's Big Adventure is correct because of the rule of compound possession. If people share something, Mignon says, they share an apostrophe-s. "So it's 'Oprah and Gayle's car,'" Mignon says. "They go on the same road trip, they share the same car, they share the same apostrophe-s."
If Oprah and Gayle have two different things, Mignon says, it is correct to use two possessives, such as, "Oprah's and Gayle's political views."