Complimentary vs. complementary

Dear Marvin,

I could not help but notice your sign in Los Angeles International Airport, offering “complimentary” shoe shining services. Unfortunately, no matter to what degree you make postive comments regarding my shoes or anything else, the shoe shine will not be “complimentary.”

“Complimentary” means “expressing a compliment,” which is in this instance an “expression of admiration.” Marvin was rather complimentary of my new shoes; he said they were the finest Crocs he had ever seen.

What you mean, Marvin, is “complementary,” an unrelated word that means “that which completes something else.” In modern parlance this is abused to mean “a free service that goes along with another service,” although the original meaning often still applies. For instance, a hotel may offer a “complementary breakfast” with your room. The breakfast service “completes” the hotel stay. We hope you enjoyed your complementary orange slice and box of milk, or as we like to call it, the Continental Breakfast.

In your case, Marvin, the shoe shine service “completes” the airline’s services, which is a bit of a stretch, although in the context of a business trip it makes some sense. But what you’re really trying to say colloquially is that your service is free.

The word you want is “complementary.”