Words matter. You want to get it right. So when it comes to ketchup versus catsup, which should you be using?

Ketchup.

See? See? I can get to the point. But I’m still going to ramble on about all the fun background bits. Like this, from our Department of Repetitive Redundancy: is “tomato” a needless modifier in tomato ketchup?

Actually, it isn’t. Tomato flavored ketchup is so much more popular in the United States that we forget about the original flavor: fish.

Funny that fish ketchup didn’t catch on here. It was the original flavor of ketchup for hundreds of years in China. Called ke-tsiap (as best we can spell it), it was a salty fermented condiment usually just called “sauce.” Like so many things, traders brought it to Europe and manufacturers began tinkering with the ingredients. There are a few other flavors available today, which nobody eats. But catsup is a little closer to the original pronunciation.

Tomato catsup became a popular staple in England, appearing in ads in the 1800s, using both spellings. Heinz began marketing it in the U.S. as Tomato Ketchup, then Catsup, then back to Ketchup again. Del Monte came out with a similar product, but labeled it Catsup so as not to be too much of a copycat. Consumers were left to figure out which was correct, and to discover the two were pretty much the same thing.

Sometime around 1988, Del Monte, seeing that most people were using the spelling ketchup, switched their labeling to match. Some companies go so far as to drop the word tomato from the label, since no one seems interested in any other flavor. I suppose you could count Heinz “Mayochup Saucy Sauce,” a mix of mayonnaise and ketchup—and apparently, sauce that is saucy. (Seriously, how much do their marketing folks get paid?) But in the end we’re all leaning hard toward ketchup, so if you want to run with the popular kids, that’s your spelling.