About 8 million English Wikipedia articles are visited every hour of every day, yet only a tiny fraction of readers click the 'edit' button in the top right corner of every page.
Bryan Henderson is not most users. The 51-year-old software engineer has a pet peeve when it comes to people who misuse the phrase "comprised of." Under the moniker Giraffedata, he's made more than 47,000 edits to the site since 2007.
Joining the show to talk more about is another man with a deep passion for grammar, Ben Zimmer, executive editor of vocabulary dot com and language columnist with the Wall Street Journal
You can read Henderson's case for why you shouldn't use "comprised of" here.