‘Regime’ Versus ‘Regimen’

These words differ by only one letter, but they mean different things. I have a memory trick to help you get them right.

Mignon Fogarty
2-minute read
The Quick And Dirty

Add a letter to the end and change the meaning.

Regime. A type of government or ruling structure.
Regimen. A course of behavior or treatment.
Regiment. A group of military forces.

Today I'll answer a question from Regina in Ecuador:

"I very much enjoy every email I get from you, and now I have a question. Can you explain the difference between the usage of the word 'regime' and 'regimen'?  There are many times when I read either word and wonder if the writer is using it correctly. This is Regina in Ecuador. Thanks a lot. Bye.”


A regime, sometimes spelled with an accented E (“régime”), is a type of government or ruling structure.

Squiggly didn’t want to live under a totalitarian regime.


A regimen is a course of behavior or treatment. Your doctor may recommend a diet or exercise regimen.

Squiggly struggled to set up a regimen, and he never knew what he should eat for dinner.

Both “regime” and “regimen” come from the Latin word for “guidance.” Since the root won’t help you remember the difference between these two words, look at it this way: 

“Regimen” is just the word “regime” with the letter N tacked on to the end. Think of the N as a doctor putting you on notice—N for “notice”— that you’d better follow a healthy regimen.


Even though Regina didn’t ask, I’ll add another noun that gets mixed up in here: “regiment.” A regiment is a group of military forces. And it comes from a different Latin word that means “government.”

Don’t punish the whole regiment for the mistakes of one.

How can you remember this one? Well, this might be a stretch, but “regiment” is just “regimen” with a T tacked on to the end. When I was a kid, I loved the movie “Monty Python and the Holy Grail,” and Sir Galahad wore a costume that had a bold and memorable big red cross on it, which looks like the letter T. He was one of the Knights of the Round Table, so he was part of a regiment. So you can think of that red T on Galahad’s shield as the T on the end of "regiment," a group of military forces. I warned you that it is a stretch, but it works for me, so I hope it will work for some of you!

Thanks for the question, Regina.

Image via Alan Cleaver at Flickr. CC BY 2.0

About the Author

Mignon Fogarty

Mignon Fogarty is the founder of Quick and Dirty Tips and the author of seven books on language, including the New York Times bestseller "Grammar Girl's Quick and Dirty Tips for Better Writing." She is an inductee in the Podcasting Hall of Fame, and the show is a five-time winner of Best Education Podcast in the Podcast Awards. She has appeared as a guest expert on the Oprah Winfrey Show and the Today Show. Her popular LinkedIn Learning courses help people write better to communicate better.