Everyone’s pumped for the return of the American version of the TV show Whose Line is it Anyway? on CW. But in all the excitement, I’ve repeatedly seen a word choice error that makes my hair stand on end: too many people are apparently looking forward to watching a mysterious show called Who’s Line is it Anyway? instead.

I think the trouble stems from over learning the rule about apostrophes being used to denote possession. In this case, the apostrophe in who’s is only to indicate a contraction (of who is or who has). When you’re talking about something belonging to someone or something, you’ll instead want whose. Here are some examples.

Who’s coming to dinner? Jim, whose cooking is amazing, is waiting for us.

Whose team will win? Dana, who’s cheering for the Packers, is optimistic.

Unlike on Whose Line (“Where everything’s made up and the points don’t matter”), the rules of grammar do matter. If you don’t want to look like a writer whose grasp of English is subpar, or someone who’s still in middle school, you’d better learn the difference between whose and who’s.