A listener named Katie wrote in with this question:
How do you show possession to more than one noun?
For example, would you say, “Tom and Jerry’s TV show” and “Ryan and my anniversary”? The latter looks so odd that I end up avoiding it entirely and going with a longer and less efficient, “Ryan and I are celebrating our anniversary on…”
Thanks for the question, Katie! What you’re asking about is called “compound possession” or “joint possession.”
I’ll start with the first part of your question.
1. With Nouns, How You Write a Compound Possessive Depends on Whether Things Are Shared
If you’re trying to write about possession and you have two subjects that are nouns, you have to decide if the two people possess something together or separately.
If the two people have the thing together, they can share the apostrophe-S. If they don’t share the thing, then they can’t share the apostrophe-S either. They each need their own.
So, to use your example, if you’re talking about Tom and Jerry’s TV show, they’re the main characters on the same cartoon about a cat and mouse—essentially they share the show—so they can share the marker of possession, and you need only one apostrophe-S at the end: It’s Tom and Jerry’s TV show.
If they are on the same show, it’s ‘Tom and Jerry’s show.’
But let’s say you’re talking about two characters who each have their own TV show. Imagine that Tom hosts a show about famous cats for Animal Planet, and Jerry hosts a spin-off of “MTV Cribs” that is all about tricked out mouse habitats. Now imagine that both those shows got canceled. You’d need to write that “Tom’s and Jerry’s shows were canceled,” putting an apostrophe-S after both “Tom” and “Jerry.” Because Tom and Jerry each have their own separate show, they each also need their own apostrophe-S in that sentence.
If they are on different shows, it’s ‘Tom’s and Jerry’s shows.’
The same is true if you have more than two people in your sentence: If they all share the same thing, you put one apostrophe-S on the final name in the list. If you want to include the bulldog Spike from the cartoon show, you can call it “Tom, Jerry, and Spike’s show.”
If they all have different things, they each need their own apostrophe-S, although that can get cumbersome. If Spike had a show on HGTV about…